10-K – 2026-02-19 – onb-20251231.htm

onb-20251231 false 2025 FY 0000707179 P1D http://fasb.org/us-gaap/2025#FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest http://fasb.org/us-gaap/2025#FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest P5M15D P7M27D P7M9D 7.197260273972603 6 7.197260273972603 7 7.197260273972603 6.394520547945206 6.098630136986301 8.591780821917808 8.197260273972603 http://fasb.org/us-gaap/2025#InterestReceivableAndOtherAssets http://fasb.org/us-gaap/2025#InterestReceivableAndOtherAssets http://fasb.org/us-gaap/2025#AccruedLiabilitiesAndOtherLiabilities http://fasb.org/us-gaap/2025#AccruedLiabilitiesAndOtherLiabilities http://fasb.org/us-gaap/2025#PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization http://fasb.org/us-gaap/2025#PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization http://fasb.org/us-gaap/2025#OtherBorrowings http://fasb.org/us-gaap/2025#OtherBorrowings http://fasb.org/us-gaap/2025#InterestReceivableAndOtherAssets http://fasb.org/us-gaap/2025#InterestReceivableAndOtherAssets http://fasb.org/us-gaap/2025#NoninterestExpense http://fasb.org/us-gaap/2025#NoninterestExpense http://fasb.org/us-gaap/2025#IncomeTaxExpenseBenefit http://fasb.org/us-gaap/2025#IncomeTaxExpenseBenefit http://fasb.org/us-gaap/2025#NoninterestExpense http://fasb.org/us-gaap/2025#NoninterestExpense http://fasb.org/us-gaap/2025#IncomeTaxExpenseBenefit http://fasb.org/us-gaap/2025#IncomeTaxExpenseBenefit http://fasb.org/us-gaap/2025#IncomeTaxExpenseBenefit http://fasb.org/us-gaap/2025#IncomeTaxExpenseBenefit http://fasb.org/us-gaap/2025#IncomeTaxExpenseBenefit http://fasb.org/us-gaap/2025#IncomeTaxExpenseBenefit iso4217:USD xbrli:shares iso4217:USD xbrli:shares xbrli:pure onb:security onb:portfolio onb:segment onb:property 0000707179 2025-01-01 2025-12-31 0000707179 us-gaap:CommonStockMember 2025-01-01 2025-12-31 0000707179 onb:DepositarySharesEachRepresentingA140thInterestInAShareOfNonCumulativePerpetualPreferredStockSeriesAMember 2025-01-01 2025-12-31 0000707179 onb:DepositarySharesEachRepresentingA140thInterestInAShareOfNonCumulativePerpetualPreferredStockSeriesCMember 2025-01-01 2025-12-31 0000707179 2025-06-30 0000707179 2026-01-31 0000707179 2025-12-31 0000707179 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember 2024-12-31 0000707179 us-gaap:ConsumerPortfolioSegmentMember 2025-12-31 0000707179 us-gaap:ConsumerPortfolioSegmentMember 2024-12-31 0000707179 2024-01-01 2024-12-31 0000707179 2023-01-01 2023-12-31 0000707179 us-gaap:PreferredStockMember 2022-12-31 0000707179 us-gaap:CommonStockMember 2022-12-31 0000707179 us-gaap:AdditionalPaidInCapitalMember 2022-12-31 0000707179 us-gaap:RetainedEarningsMember 2022-12-31 0000707179 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2022-12-31 0000707179 2022-12-31 0000707179 us-gaap:RetainedEarningsMember 2023-01-01 2023-12-31 0000707179 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2023-01-01 2023-12-31 0000707179 us-gaap:CommonStockMember 2023-01-01 2023-12-31 0000707179 us-gaap:AdditionalPaidInCapitalMember 2023-01-01 2023-12-31 0000707179 us-gaap:PreferredStockMember 2023-12-31 0000707179 us-gaap:CommonStockMember 2023-12-31 0000707179 us-gaap:AdditionalPaidInCapitalMember 2023-12-31 0000707179 us-gaap:RetainedEarningsMember 2023-12-31 0000707179 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2023-12-31 0000707179 2023-12-31 0000707179 us-gaap:RetainedEarningsMember 2024-01-01 2024-12-31 0000707179 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommonStockMember 2024-01-01 2024-12-31 0000707179 us-gaap:AdditionalPaidInCapitalMember 2024-01-01 2024-12-31 0000707179 us-gaap:PreferredStockMember 2024-12-31 0000707179 us-gaap:CommonStockMember 2024-12-31 0000707179 us-gaap:AdditionalPaidInCapitalMember 2024-12-31 0000707179 us-gaap:RetainedEarningsMember 2024-12-31 0000707179 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2024-12-31 0000707179 us-gaap:RetainedEarningsMember 2025-01-01 2025-12-31 0000707179 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommonStockMember 2025-01-01 2025-12-31 0000707179 us-gaap:AdditionalPaidInCapitalMember 2025-01-01 2025-12-31 0000707179 us-gaap:PreferredStockMember 2025-12-31 0000707179 us-gaap:CommonStockMember 2025-12-31 0000707179 us-gaap:AdditionalPaidInCapitalMember 2025-12-31 0000707179 us-gaap:RetainedEarningsMember 2025-12-31 0000707179 us-gaap:AccumulatedOtherComprehensiveIncomeMember 2025-12-31 0000707179 srt:MinimumMember us-gaap:BuildingAndBuildingImprovementsMember 2025-12-31 0000707179 srt:MaximumMember us-gaap:BuildingAndBuildingImprovementsMember 2025-12-31 0000707179 srt:MinimumMember us-gaap:FurnitureAndFixturesMember 2025-12-31 0000707179 srt:MaximumMember us-gaap:FurnitureAndFixturesMember 2025-12-31 0000707179 srt:MinimumMember onb:CoreDepositsAndOtherIntangibleAssetsMember 2025-12-31 0000707179 srt:MaximumMember onb:CoreDepositsAndOtherIntangibleAssetsMember 2025-12-31 0000707179 srt:MinimumMember 2025-01-01 2025-12-31 0000707179 srt:MaximumMember 2025-01-01 2025-12-31 0000707179 srt:ParentCompanyMember 2023-01-01 2023-12-31 0000707179 srt:ParentCompanyMember 2024-01-01 2024-12-31 0000707179 srt:ParentCompanyMember 2025-01-01 2025-12-31 0000707179 onb:BremerMember 2025-05-01 2025-05-31 0000707179 onb:CapStarFinancialHoldingsIncMember 2024-04-01 2024-04-30 0000707179 onb:BremerMember 2025-05-01 0000707179 onb:BremerMember onb:CitibankN.AMember 2024-11-25 2024-11-25 0000707179 onb:BremerMember onb:CitibankN.AMember 2024-11-25 0000707179 onb:BremerMember onb:CitigroupGlobalMarketsInc.Member 2024-11-25 2024-11-25 0000707179 onb:BremerMember onb:CitigroupGlobalMarketsInc.Member 2025-05-23 2025-05-23 0000707179 onb:BremerMember onb:CitigroupGlobalMarketsInc.Member 2025-05-23 0000707179 onb:BremerMember us-gaap:CommonStockMember 2025-05-01 2025-05-01 0000707179 onb:BremerMember us-gaap:CommonStockMember 2025-05-01 0000707179 onb:BremerMember 2025-05-01 2025-05-01 0000707179 onb:BremerMember us-gaap:CoreDepositsMember 2025-05-01 0000707179 onb:BremerMember us-gaap:CustomerRelationshipsMember 2025-05-01 0000707179 onb:BremerMember 2025-01-01 2025-12-31 0000707179 onb:BremerMember us-gaap:AcquisitionRelatedCostsMember 2025-01-01 2025-12-31 0000707179 onb:BremerMember onb:BusinessCombinationProFormaInformationNonrecurringAdjustmentProvisionForCreditLossesOnUnfundedLoanCommitmentsMember 2025-01-01 2025-12-31 0000707179 onb:BremerMember onb:BusinessCombinationProFormaInformationNonrecurringAdjustmentProvisionForCreditLossesLoansAcquiredMember 2025-01-01 2025-12-31 0000707179 onb:BremerMember onb:BusinessCombinationProFormaInformationNonrecurringAdjustmentBenefitFreezingAndSubsequentTerminationMember 2025-01-01 2025-12-31 0000707179 onb:CapStarFinancialHoldingsIncMember 2024-04-01 0000707179 onb:CapStarFinancialHoldingsIncMember us-gaap:CommonStockMember 2024-04-01 2024-04-01 0000707179 onb:CapStarFinancialHoldingsIncMember us-gaap:CommonStockMember 2024-04-01 0000707179 onb:CapStarFinancialHoldingsIncMember 2024-04-01 2024-04-01 0000707179 onb:CapStarFinancialHoldingsIncMember us-gaap:CoreDepositsMember 2024-04-01 0000707179 2024-04-01 2024-04-01 0000707179 onb:CapStarFinancialHoldingsIncMember 2025-01-01 2025-12-31 0000707179 onb:CapStarFinancialHoldingsIncMember 2024-01-01 2024-12-31 0000707179 us-gaap:USTreasurySecuritiesMember 2025-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember 2025-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember 2025-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember 2025-12-31 0000707179 onb:PooledTrustPreferredSecuritiesMember 2025-12-31 0000707179 us-gaap:OtherDebtSecuritiesMember 2025-12-31 0000707179 us-gaap:USTreasurySecuritiesMember 2024-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember 2024-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember 2024-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember 2024-12-31 0000707179 onb:PooledTrustPreferredSecuritiesMember 2024-12-31 0000707179 us-gaap:OtherDebtSecuritiesMember 2024-12-31 0000707179 us-gaap:OtherAssetsMember 2025-12-31 0000707179 us-gaap:OtherAssetsMember 2024-12-31 0000707179 us-gaap:OtherAssetsMember srt:PartnershipInterestMember 2025-12-31 0000707179 us-gaap:OtherAssetsMember onb:InitiativesInLowToModerateIncomeNeighborhoodsMember 2025-12-31 0000707179 us-gaap:OtherAssetsMember srt:PartnershipInterestMember 2024-12-31 0000707179 us-gaap:OtherAssetsMember onb:InitiativesInLowToModerateIncomeNeighborhoodsMember 2024-12-31 0000707179 srt:MaximumMember 2024-12-31 0000707179 srt:MaximumMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2025-12-31 0000707179 us-gaap:ConsumerPortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2025-12-31 0000707179 onb:SegmentPortfolioReclassificationMember 2025-12-31 0000707179 onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2024-12-31 0000707179 us-gaap:ConsumerPortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:SegmentPortfolioReclassificationMember 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2024-12-31 0000707179 onb:SegmentPortfolioReclassificationMember 2024-12-31 0000707179 onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2024-12-31 0000707179 us-gaap:FinanceLeasesPortfolioSegmentMember 2025-12-31 0000707179 us-gaap:FinanceLeasesPortfolioSegmentMember 2024-12-31 0000707179 onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2025-01-01 2025-12-31 0000707179 onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2024-01-01 2024-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember us-gaap:CommercialPortfolioSegmentMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember 2025-01-01 2025-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember us-gaap:CommercialRealEstatePortfolioSegmentMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember 2025-01-01 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember 2024-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember onb:BusinessBankingCreditCenterPortfolioSegmentMember 2025-01-01 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember 2025-01-01 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember 2025-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember us-gaap:ResidentialPortfolioSegmentMember 2025-01-01 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember 2025-01-01 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember 2024-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember onb:IndirectPortfolioSegmentMember 2025-01-01 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember 2025-01-01 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember 2024-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember onb:DirectPortfolioSegmentMember 2025-01-01 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember 2025-01-01 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember 2024-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember onb:HomeEquityPortfolioSegmentMember 2025-01-01 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember 2025-01-01 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember 2025-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember 2023-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember us-gaap:CommercialPortfolioSegmentMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember 2023-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember us-gaap:CommercialRealEstatePortfolioSegmentMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember 2024-01-01 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember 2023-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember onb:BusinessBankingCreditCenterPortfolioSegmentMember 2024-01-01 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember 2024-01-01 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember 2023-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember us-gaap:ResidentialPortfolioSegmentMember 2024-01-01 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember 2024-01-01 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember 2023-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember onb:IndirectPortfolioSegmentMember 2024-01-01 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember 2024-01-01 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember 2023-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember onb:DirectPortfolioSegmentMember 2024-01-01 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember 2024-01-01 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember 2023-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember onb:HomeEquityPortfolioSegmentMember 2024-01-01 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember 2024-01-01 2024-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember 2022-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember us-gaap:CommercialPortfolioSegmentMember 2023-01-01 2023-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember 2023-01-01 2023-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember 2022-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember us-gaap:CommercialRealEstatePortfolioSegmentMember 2023-01-01 2023-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember 2023-01-01 2023-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember 2022-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember onb:BusinessBankingCreditCenterPortfolioSegmentMember 2023-01-01 2023-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember 2023-01-01 2023-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember 2022-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember us-gaap:ResidentialPortfolioSegmentMember 2023-01-01 2023-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember 2023-01-01 2023-12-31 0000707179 onb:IndirectPortfolioSegmentMember 2022-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember onb:IndirectPortfolioSegmentMember 2023-01-01 2023-12-31 0000707179 onb:IndirectPortfolioSegmentMember 2023-01-01 2023-12-31 0000707179 onb:DirectPortfolioSegmentMember 2022-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember onb:DirectPortfolioSegmentMember 2023-01-01 2023-12-31 0000707179 onb:DirectPortfolioSegmentMember 2023-01-01 2023-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember 2022-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember onb:HomeEquityPortfolioSegmentMember 2023-01-01 2023-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember 2023-01-01 2023-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember 2023-01-01 2023-12-31 0000707179 us-gaap:UnfundedLoanCommitmentMember 2024-12-31 0000707179 us-gaap:UnfundedLoanCommitmentMember 2023-12-31 0000707179 us-gaap:UnfundedLoanCommitmentMember 2022-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember us-gaap:UnfundedLoanCommitmentMember 2025-01-01 2025-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember us-gaap:UnfundedLoanCommitmentMember 2024-01-01 2024-12-31 0000707179 srt:CumulativeEffectPeriodOfAdoptionAdjustedBalanceMember us-gaap:UnfundedLoanCommitmentMember 2023-01-01 2023-12-31 0000707179 us-gaap:UnfundedLoanCommitmentMember 2025-01-01 2025-12-31 0000707179 us-gaap:UnfundedLoanCommitmentMember 2024-01-01 2024-12-31 0000707179 us-gaap:UnfundedLoanCommitmentMember 2023-01-01 2023-12-31 0000707179 us-gaap:UnfundedLoanCommitmentMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:PassMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:SpecialMentionMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:SubstandardMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember onb:NonAccrualMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:DoubtfulMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:PassMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:SpecialMentionMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:SubstandardMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember onb:NonAccrualMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:DoubtfulMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:PassMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:SpecialMentionMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:SubstandardMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember onb:NonAccrualMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:DoubtfulMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:PassMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:SpecialMentionMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:SubstandardMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember onb:NonAccrualMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:DoubtfulMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:PassMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:SpecialMentionMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:SubstandardMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember onb:NonAccrualMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:DoubtfulMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:PassMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:SpecialMentionMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:SubstandardMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember onb:NonAccrualMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:DoubtfulMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:PerformingFinancingReceivableMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:NonperformingFinancingReceivableMember 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember us-gaap:PerformingFinancingReceivableMember 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember us-gaap:NonperformingFinancingReceivableMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember us-gaap:PerformingFinancingReceivableMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember us-gaap:NonperformingFinancingReceivableMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember us-gaap:PerformingFinancingReceivableMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember us-gaap:NonperformingFinancingReceivableMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:PerformingFinancingReceivableMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:NonperformingFinancingReceivableMember 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember us-gaap:PerformingFinancingReceivableMember 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember us-gaap:NonperformingFinancingReceivableMember 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember us-gaap:PerformingFinancingReceivableMember 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember us-gaap:NonperformingFinancingReceivableMember 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember us-gaap:PerformingFinancingReceivableMember 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember us-gaap:NonperformingFinancingReceivableMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2025-01-01 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2024-01-01 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2023-01-01 2023-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2023-01-01 2023-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember 2023-01-01 2023-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2025-12-31 0000707179 onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2025-12-31 0000707179 onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2025-12-31 0000707179 onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2025-12-31 0000707179 onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2025-12-31 0000707179 onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2024-12-31 0000707179 onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2024-12-31 0000707179 onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2024-12-31 0000707179 onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2024-12-31 0000707179 onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetPastDueMember 2024-12-31 0000707179 onb:SegmentPortfolioReclassificationAdjustedBalanceMember us-gaap:FinancialAssetNotPastDueMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:RealEstateMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:BlanketLienCollateralMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:InvestmentSecuritiesAndCashCollateralMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:AutomobilesMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:OtherCollateralMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:RealEstateMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:BlanketLienCollateralMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:InvestmentSecuritiesAndCashCollateralMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:AutomobilesMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:OtherCollateralMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember us-gaap:RealEstateMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:BlanketLienCollateralMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:InvestmentSecuritiesAndCashCollateralMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember us-gaap:AutomobilesMember 2025-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:OtherCollateralMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:RealEstateMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:BlanketLienCollateralMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:InvestmentSecuritiesAndCashCollateralMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:AutomobilesMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:OtherCollateralMember 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember us-gaap:RealEstateMember 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:BlanketLienCollateralMember 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:InvestmentSecuritiesAndCashCollateralMember 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember us-gaap:AutomobilesMember 2025-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:OtherCollateralMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember us-gaap:RealEstateMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:BlanketLienCollateralMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:InvestmentSecuritiesAndCashCollateralMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember us-gaap:AutomobilesMember 2025-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:OtherCollateralMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember us-gaap:RealEstateMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:BlanketLienCollateralMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:InvestmentSecuritiesAndCashCollateralMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember us-gaap:AutomobilesMember 2025-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:OtherCollateralMember 2025-12-31 0000707179 us-gaap:RealEstateMember 2025-12-31 0000707179 onb:BlanketLienCollateralMember 2025-12-31 0000707179 onb:InvestmentSecuritiesAndCashCollateralMember 2025-12-31 0000707179 us-gaap:AutomobilesMember 2025-12-31 0000707179 onb:OtherCollateralMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:RealEstateMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:BlanketLienCollateralMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:InvestmentSecuritiesAndCashCollateralMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:AutomobilesMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:OtherCollateralMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:RealEstateMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:BlanketLienCollateralMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:InvestmentSecuritiesAndCashCollateralMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:AutomobilesMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:OtherCollateralMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember us-gaap:RealEstateMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:BlanketLienCollateralMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:InvestmentSecuritiesAndCashCollateralMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember us-gaap:AutomobilesMember 2024-12-31 0000707179 onb:BusinessBankingCreditCenterPortfolioSegmentMember onb:OtherCollateralMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:RealEstateMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:BlanketLienCollateralMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:InvestmentSecuritiesAndCashCollateralMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:AutomobilesMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:OtherCollateralMember 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember us-gaap:RealEstateMember 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:BlanketLienCollateralMember 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:InvestmentSecuritiesAndCashCollateralMember 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember us-gaap:AutomobilesMember 2024-12-31 0000707179 onb:IndirectPortfolioSegmentMember onb:OtherCollateralMember 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember us-gaap:RealEstateMember 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:BlanketLienCollateralMember 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:InvestmentSecuritiesAndCashCollateralMember 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember us-gaap:AutomobilesMember 2024-12-31 0000707179 onb:DirectPortfolioSegmentMember onb:OtherCollateralMember 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember us-gaap:RealEstateMember 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:BlanketLienCollateralMember 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:InvestmentSecuritiesAndCashCollateralMember 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember us-gaap:AutomobilesMember 2024-12-31 0000707179 onb:HomeEquityPortfolioSegmentMember onb:OtherCollateralMember 2024-12-31 0000707179 us-gaap:RealEstateMember 2024-12-31 0000707179 onb:BlanketLienCollateralMember 2024-12-31 0000707179 onb:InvestmentSecuritiesAndCashCollateralMember 2024-12-31 0000707179 us-gaap:AutomobilesMember 2024-12-31 0000707179 onb:OtherCollateralMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:ExtendedMaturityMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:PaymentDeferralMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:InterestRateBelowMarketReductionMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:ExtendedMaturityMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:PaymentDeferralMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:InterestRateBelowMarketReductionMember 2025-01-01 2025-12-31 0000707179 us-gaap:ExtendedMaturityMember 2025-01-01 2025-12-31 0000707179 us-gaap:PaymentDeferralMember 2025-01-01 2025-12-31 0000707179 us-gaap:InterestRateBelowMarketReductionMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:ExtendedMaturityMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:PaymentDeferralMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:InterestRateBelowMarketReductionMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:ExtendedMaturityMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:PaymentDeferralMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:InterestRateBelowMarketReductionMember 2024-01-01 2024-12-31 0000707179 us-gaap:ExtendedMaturityMember 2024-01-01 2024-12-31 0000707179 us-gaap:PaymentDeferralMember 2024-01-01 2024-12-31 0000707179 us-gaap:InterestRateBelowMarketReductionMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:ExtendedMaturityMember 2023-01-01 2023-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:PaymentDeferralMember 2023-01-01 2023-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:InterestRateBelowMarketReductionMember 2023-01-01 2023-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:ExtendedMaturityMember 2023-01-01 2023-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:PaymentDeferralMember 2023-01-01 2023-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:InterestRateBelowMarketReductionMember 2023-01-01 2023-12-31 0000707179 us-gaap:ExtendedMaturityMember 2023-01-01 2023-12-31 0000707179 us-gaap:PaymentDeferralMember 2023-01-01 2023-12-31 0000707179 us-gaap:InterestRateBelowMarketReductionMember 2023-01-01 2023-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:FinancialAssetPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:FinancialAssetNotPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FinancialAssetPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FinancialAssetNotPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:FinancingReceivables30To59DaysPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:FinancingReceivables60To89DaysPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:FinancialAssetPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:FinancialAssetNotPastDueMember 2025-01-01 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:FinancialAssetPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:FinancialAssetNotPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FinancingReceivables30To59DaysPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FinancingReceivables60To89DaysPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FinancialAssetPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FinancialAssetNotPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:FinancingReceivables30To59DaysPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:FinancingReceivables60To89DaysPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:FinancialAssetPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:FinancialAssetNotPastDueMember 2024-01-01 2024-12-31 0000707179 us-gaap:LandMember 2025-12-31 0000707179 us-gaap:LandMember 2024-12-31 0000707179 us-gaap:BuildingMember 2025-12-31 0000707179 us-gaap:BuildingMember 2024-12-31 0000707179 onb:FurnitureFixturesAndEquipmentMember 2025-12-31 0000707179 onb:FurnitureFixturesAndEquipmentMember 2024-12-31 0000707179 us-gaap:LeaseholdImprovementsMember 2025-12-31 0000707179 us-gaap:LeaseholdImprovementsMember 2024-12-31 0000707179 onb:BremerMember 2025-12-31 0000707179 srt:MinimumMember 2025-12-31 0000707179 onb:OccupancyOrEquipmentExpenseMember 2025-01-01 2025-12-31 0000707179 onb:OccupancyOrEquipmentExpenseMember 2024-01-01 2024-12-31 0000707179 onb:OccupancyOrEquipmentExpenseMember 2023-01-01 2023-12-31 0000707179 onb:OccupancyExpenseMember 2025-01-01 2025-12-31 0000707179 onb:OccupancyExpenseMember 2024-01-01 2024-12-31 0000707179 onb:OccupancyExpenseMember 2023-01-01 2023-12-31 0000707179 us-gaap:InterestExpenseMember 2025-01-01 2025-12-31 0000707179 us-gaap:InterestExpenseMember 2024-01-01 2024-12-31 0000707179 us-gaap:InterestExpenseMember 2023-01-01 2023-12-31 0000707179 2025-08-31 2025-08-31 0000707179 us-gaap:CoreDepositsMember 2025-12-31 0000707179 us-gaap:CustomerRelationshipsMember 2025-12-31 0000707179 us-gaap:CoreDepositsMember 2024-12-31 0000707179 us-gaap:CustomerRelationshipsMember 2024-12-31 0000707179 srt:MinimumMember us-gaap:CoreDepositsMember 2025-12-31 0000707179 srt:MaximumMember us-gaap:CoreDepositsMember 2025-12-31 0000707179 onb:BremerMember us-gaap:CoreDepositsMember 2025-01-01 2025-12-31 0000707179 onb:BremerMember us-gaap:CustomerRelationshipsMember 2025-01-01 2025-12-31 0000707179 onb:CapStarFinancialHoldingsIncMember us-gaap:CoreDepositsMember 2024-01-01 2024-12-31 0000707179 onb:LowIncomeHousingTaxCreditsMember 2025-12-31 0000707179 onb:LowIncomeHousingTaxCreditsMember 2024-12-31 0000707179 onb:FederalHistoricTaxCreditsMember 2025-12-31 0000707179 onb:FederalHistoricTaxCreditsMember 2024-12-31 0000707179 onb:NewMarketsTaxCreditMember 2025-12-31 0000707179 onb:NewMarketsTaxCreditMember 2024-12-31 0000707179 us-gaap:RenewableEnergyProgramMember 2025-12-31 0000707179 us-gaap:RenewableEnergyProgramMember 2024-12-31 0000707179 onb:LowIncomeHousingTaxCreditsMember 2025-01-01 2025-12-31 0000707179 onb:FederalHistoricTaxCreditsMember 2025-01-01 2025-12-31 0000707179 onb:NewMarketsTaxCreditMember 2025-01-01 2025-12-31 0000707179 onb:LowIncomeHousingTaxCreditsMember 2024-01-01 2024-12-31 0000707179 onb:FederalHistoricTaxCreditsMember 2024-01-01 2024-12-31 0000707179 onb:NewMarketsTaxCreditMember 2024-01-01 2024-12-31 0000707179 us-gaap:RenewableEnergyProgramMember 2024-01-01 2024-12-31 0000707179 onb:LowIncomeHousingTaxCreditsMember 2023-01-01 2023-12-31 0000707179 onb:FederalHistoricTaxCreditsMember 2023-01-01 2023-12-31 0000707179 onb:NewMarketsTaxCreditMember 2023-01-01 2023-12-31 0000707179 us-gaap:RenewableEnergyProgramMember 2023-01-01 2023-12-31 0000707179 us-gaap:USTreasurySecuritiesMember us-gaap:MaturityOvernightMember 2025-12-31 0000707179 us-gaap:USTreasurySecuritiesMember us-gaap:MaturityUpTo30DaysMember 2025-12-31 0000707179 us-gaap:USTreasurySecuritiesMember us-gaap:Maturity30To90DaysMember 2025-12-31 0000707179 us-gaap:USTreasurySecuritiesMember us-gaap:MaturityOver90DaysMember 2025-12-31 0000707179 us-gaap:USTreasurySecuritiesMember 2025-12-31 0000707179 us-gaap:MaturityOvernightMember 2025-12-31 0000707179 us-gaap:MaturityUpTo30DaysMember 2025-12-31 0000707179 us-gaap:Maturity30To90DaysMember 2025-12-31 0000707179 us-gaap:MaturityOver90DaysMember 2025-12-31 0000707179 srt:MinimumMember us-gaap:FederalHomeLoanBankAdvancesMember 2025-12-31 0000707179 srt:MaximumMember us-gaap:FederalHomeLoanBankAdvancesMember 2025-12-31 0000707179 srt:ParentCompanyMember onb:SubordinatedDebenturesMaturingSeptember2026Member us-gaap:SubordinatedDebtMember 2025-12-31 0000707179 srt:ParentCompanyMember onb:SubordinatedDebenturesMaturingSeptember2026Member us-gaap:SubordinatedDebtMember 2024-12-31 0000707179 srt:ParentCompanyMember onb:SubordinatedDebenturesMaturingSeptember2030Member us-gaap:SubordinatedDebtMember 2025-12-31 0000707179 srt:ParentCompanyMember onb:SubordinatedDebenturesMaturingSeptember2030Member us-gaap:SubordinatedDebtMember 2024-12-31 0000707179 srt:ParentCompanyMember srt:MinimumMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 srt:ParentCompanyMember srt:MaximumMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 us-gaap:JuniorSubordinatedDebtMember srt:ParentCompanyMember 2025-12-31 0000707179 us-gaap:JuniorSubordinatedDebtMember srt:ParentCompanyMember 2024-12-31 0000707179 onb:OldNationalBankMember 2025-12-31 0000707179 onb:OldNationalBankMember 2024-12-31 0000707179 onb:OldNationalBankMember us-gaap:SubordinatedDebtMember 2025-12-31 0000707179 onb:OldNationalBankMember us-gaap:SubordinatedDebtMember 2024-12-31 0000707179 srt:MinimumMember onb:OldNationalBankMember us-gaap:NotesPayableToBanksMember 2025-12-31 0000707179 srt:MaximumMember onb:OldNationalBankMember us-gaap:NotesPayableToBanksMember 2025-12-31 0000707179 onb:OldNationalBankMember us-gaap:NotesPayableToBanksMember 2025-12-31 0000707179 onb:OldNationalBankMember us-gaap:NotesPayableToBanksMember 2024-12-31 0000707179 onb:OldNationalBankMember 2025-01-01 2025-12-31 0000707179 onb:OldNationalBankMember 2024-01-01 2024-12-31 0000707179 onb:BridgeviewStatutoryTrustIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 onb:BridgeviewStatutoryTrustIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-01-01 2025-12-31 0000707179 onb:BridgeviewCapitalTrustIIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 onb:BridgeviewCapitalTrustIIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-01-01 2025-12-31 0000707179 onb:FirstMidwestCapitalTrustIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 onb:StJosephCapitalTrustIIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 onb:StJosephCapitalTrustIIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-01-01 2025-12-31 0000707179 onb:NorthernStatesStatutoryTrustIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 onb:NorthernStatesStatutoryTrustIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-01-01 2025-12-31 0000707179 onb:AnchorCapitalTrustIIIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 onb:AnchorCapitalTrustIIIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-01-01 2025-12-31 0000707179 onb:GreatLakesStatutoryTrustIIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 onb:GreatLakesStatutoryTrustIIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-01-01 2025-12-31 0000707179 onb:BremerStatutoryTrustIIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 onb:BremerStatutoryTrustIIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-01-01 2025-12-31 0000707179 onb:HomeFederalStatutoryTrustIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 onb:HomeFederalStatutoryTrustIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-01-01 2025-12-31 0000707179 onb:MonroeBancorpCapitalTrustIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 onb:MonroeBancorpCapitalTrustIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-01-01 2025-12-31 0000707179 onb:TowerCapitalTrustThreeMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 onb:TowerCapitalTrustThreeMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-01-01 2025-12-31 0000707179 onb:MonroeBancorpStatutoryTrustIiMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 onb:MonroeBancorpStatutoryTrustIiMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-01-01 2025-12-31 0000707179 onb:GreatLakesStatutoryTrustIIIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 onb:GreatLakesStatutoryTrustIIIMember onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-01-01 2025-12-31 0000707179 onb:TrustPreferredSecuritiesMember us-gaap:JuniorSubordinatedDebtMember 2025-12-31 0000707179 onb:SubordinatedNoteMaturingJanuary2026Member us-gaap:SubordinatedDebtMember us-gaap:SubsequentEventMember 2026-01-29 0000707179 onb:SubordinatedNoteMaturingJanuary2026Member us-gaap:SubordinatedDebtMember us-gaap:SubsequentEventMember 2026-01-29 2026-01-29 0000707179 us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember 2024-12-31 0000707179 onb:AccumulatedUnrealizedGainsLossesOnHeldToMaturitySecuritiesParentMember 2024-12-31 0000707179 us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2024-12-31 0000707179 us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2024-12-31 0000707179 us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember 2025-01-01 2025-12-31 0000707179 onb:AccumulatedUnrealizedGainsLossesOnHeldToMaturitySecuritiesParentMember 2025-01-01 2025-12-31 0000707179 us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2025-01-01 2025-12-31 0000707179 us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2025-01-01 2025-12-31 0000707179 us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember 2025-12-31 0000707179 onb:AccumulatedUnrealizedGainsLossesOnHeldToMaturitySecuritiesParentMember 2025-12-31 0000707179 us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2025-12-31 0000707179 us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2025-12-31 0000707179 us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember 2023-12-31 0000707179 onb:AccumulatedUnrealizedGainsLossesOnHeldToMaturitySecuritiesParentMember 2023-12-31 0000707179 us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2023-12-31 0000707179 us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2023-12-31 0000707179 us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember 2024-01-01 2024-12-31 0000707179 onb:AccumulatedUnrealizedGainsLossesOnHeldToMaturitySecuritiesParentMember 2024-01-01 2024-12-31 0000707179 us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2024-01-01 2024-12-31 0000707179 us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2024-01-01 2024-12-31 0000707179 us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember 2022-12-31 0000707179 onb:AccumulatedUnrealizedGainsLossesOnHeldToMaturitySecuritiesParentMember 2022-12-31 0000707179 us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2022-12-31 0000707179 us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2022-12-31 0000707179 us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember 2023-01-01 2023-12-31 0000707179 onb:AccumulatedUnrealizedGainsLossesOnHeldToMaturitySecuritiesParentMember 2023-01-01 2023-12-31 0000707179 us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2023-01-01 2023-12-31 0000707179 us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2023-01-01 2023-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember 2025-01-01 2025-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember 2024-01-01 2024-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember 2023-01-01 2023-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember onb:AccumulatedUnrealizedGainsLossesOnHeldToMaturitySecuritiesParentMember 2025-01-01 2025-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember onb:AccumulatedUnrealizedGainsLossesOnHeldToMaturitySecuritiesParentMember 2024-01-01 2024-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember onb:AccumulatedUnrealizedGainsLossesOnHeldToMaturitySecuritiesParentMember 2023-01-01 2023-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2025-01-01 2025-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2024-01-01 2024-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember us-gaap:AccumulatedGainLossNetCashFlowHedgeParentMember 2023-01-01 2023-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2025-01-01 2025-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2024-01-01 2024-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember us-gaap:AccumulatedDefinedBenefitPlansAdjustmentMember 2023-01-01 2023-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember 2025-01-01 2025-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember 2024-01-01 2024-12-31 0000707179 us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember 2023-01-01 2023-12-31 0000707179 us-gaap:DomesticCountryMember 2025-12-31 0000707179 us-gaap:DomesticCountryMember 2024-12-31 0000707179 us-gaap:StateAndLocalJurisdictionMember 2025-12-31 0000707179 us-gaap:StateAndLocalJurisdictionMember 2024-12-31 0000707179 onb:FirstMidwestBancorpIncMember 2024-12-31 0000707179 onb:FirstMidwestBancorpIncMember 2023-12-31 0000707179 onb:FirstMidwestBancorpIncMember 2022-12-31 0000707179 onb:FirstMidwestBancorpIncMember 2025-01-01 2025-12-31 0000707179 onb:FirstMidwestBancorpIncMember 2024-01-01 2024-12-31 0000707179 onb:FirstMidwestBancorpIncMember 2023-01-01 2023-12-31 0000707179 onb:FirstMidwestBancorpIncMember 2025-12-31 0000707179 stpr:MN 2025-01-01 2025-12-31 0000707179 stpr:MN 2024-01-01 2024-12-31 0000707179 stpr:MN 2023-01-01 2023-12-31 0000707179 stpr:IL 2025-01-01 2025-12-31 0000707179 stpr:IL 2024-01-01 2024-12-31 0000707179 stpr:IL 2023-01-01 2023-12-31 0000707179 us-gaap:StateAndLocalTaxJurisdictionOtherMember 2025-01-01 2025-12-31 0000707179 us-gaap:StateAndLocalTaxJurisdictionOtherMember 2024-01-01 2024-12-31 0000707179 us-gaap:StateAndLocalTaxJurisdictionOtherMember 2023-01-01 2023-12-31 0000707179 us-gaap:RestrictedStockMember onb:AnnuallyMember 2025-01-01 2025-12-31 0000707179 us-gaap:RestrictedStockMember 2024-12-31 0000707179 us-gaap:RestrictedStockMember 2023-12-31 0000707179 us-gaap:RestrictedStockMember 2025-01-01 2025-12-31 0000707179 us-gaap:RestrictedStockMember 2024-01-01 2024-12-31 0000707179 us-gaap:RestrictedStockMember 2025-12-31 0000707179 us-gaap:RestrictedStockMember 2023-01-01 2023-12-31 0000707179 us-gaap:PerformanceSharesMember 2025-01-01 2025-12-31 0000707179 us-gaap:PerformanceSharesMember 2024-12-31 0000707179 us-gaap:PerformanceSharesMember 2023-12-31 0000707179 us-gaap:PerformanceSharesMember 2024-01-01 2024-12-31 0000707179 us-gaap:PerformanceSharesMember 2025-12-31 0000707179 us-gaap:EmployeeStockOptionMember srt:ParentCompanyMember 2025-01-01 2025-12-31 0000707179 onb:AmendedAndRestatedTwoThousandEightIncentiveCompensationPlanMember onb:OutsideDirectorStockCompensationProgramMember 2025-12-31 0000707179 onb:AmendedAndRestatedTwoThousandEightIncentiveCompensationPlanMember onb:OutsideDirectorStockCompensationProgramMember 2024-12-31 0000707179 onb:AmendedAndRestatedTwoThousandEightIncentiveCompensationPlanMember onb:OutsideDirectorStockCompensationProgramMember 2023-12-31 0000707179 onb:EmployerMatchingContributionTrancheOneMember 2025-01-01 2025-12-31 0000707179 onb:DividendReinvestmentAndStockPurchasePlanMember 2024-08-13 0000707179 onb:DividendReinvestmentAndStockPurchasePlanMember 2025-12-31 0000707179 onb:EmployeeStockPurchasePlanMember 2025-01-01 2025-12-31 0000707179 onb:EmployeeStockPurchasePlanMember 2024-01-01 2024-12-31 0000707179 onb:ShareRepurchasePlanMember 2025-03-31 0000707179 onb:ShareRepurchasePlanMember 2025-01-01 2025-12-31 0000707179 onb:ShareRepurchasePlanMember srt:ScenarioForecastMember 2026-03-31 0000707179 us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember 2025-12-31 0000707179 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:USTreasurySecuritiesMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember 2025-12-31 0000707179 us-gaap:USTreasurySecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:USTreasurySecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:USTreasurySecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember 2025-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember 2025-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember 2025-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 onb:PooledTrustPreferredSecuritiesMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember 2025-12-31 0000707179 onb:PooledTrustPreferredSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 onb:PooledTrustPreferredSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 onb:PooledTrustPreferredSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:OtherDebtSecuritiesMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember 2025-12-31 0000707179 us-gaap:OtherDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:OtherDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:OtherDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember 2024-12-31 0000707179 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 us-gaap:USTreasurySecuritiesMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember 2024-12-31 0000707179 us-gaap:USTreasurySecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:USTreasurySecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:USTreasurySecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember 2024-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember 2024-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember 2024-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 onb:PooledTrustPreferredSecuritiesMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember 2024-12-31 0000707179 onb:PooledTrustPreferredSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 onb:PooledTrustPreferredSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 onb:PooledTrustPreferredSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 us-gaap:OtherDebtSecuritiesMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember 2024-12-31 0000707179 us-gaap:OtherDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:OtherDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:OtherDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsRecurringMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 onb:CommercialRealEstateForeclosedAssetsMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember 2025-12-31 0000707179 onb:CommercialRealEstateForeclosedAssetsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 onb:CommercialRealEstateForeclosedAssetsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 onb:CommercialRealEstateForeclosedAssetsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 onb:ResidentialForeclosedAssetsMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember 2025-12-31 0000707179 onb:ResidentialForeclosedAssetsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 onb:ResidentialForeclosedAssetsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 onb:ResidentialForeclosedAssetsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 onb:ImpairedCommercialAndCommercialRealEstateLoansMember 2025-12-31 0000707179 onb:ImpairedCommercialAndCommercialRealEstateLoansMember 2025-01-01 2025-12-31 0000707179 us-gaap:FairValueMeasurementsNonrecurringMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 onb:CommercialRealEstateForeclosedAssetsMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember 2024-12-31 0000707179 onb:CommercialRealEstateForeclosedAssetsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 onb:CommercialRealEstateForeclosedAssetsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 onb:CommercialRealEstateForeclosedAssetsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 onb:ResidentialForeclosedAssetsMember us-gaap:CarryingReportedAmountFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember 2024-12-31 0000707179 onb:ResidentialForeclosedAssetsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 onb:ResidentialForeclosedAssetsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 onb:ResidentialForeclosedAssetsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueMeasurementsNonrecurringMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 onb:ImpairedCommercialAndCommercialRealEstateLoansMember 2024-12-31 0000707179 onb:ImpairedCommercialAndCommercialRealEstateLoansMember 2024-01-01 2024-12-31 0000707179 us-gaap:FairValueMeasurementsNonrecurringMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:CollateralDependentImpairedLoansMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember 2025-12-31 0000707179 onb:CollateralDependentImpairedLoansMember us-gaap:MeasurementInputDiscountRateMember us-gaap:CommercialPortfolioSegmentMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:MinimumMember 2025-12-31 0000707179 onb:CollateralDependentImpairedLoansMember us-gaap:MeasurementInputDiscountRateMember us-gaap:CommercialPortfolioSegmentMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:MaximumMember 2025-12-31 0000707179 onb:CollateralDependentImpairedLoansMember us-gaap:MeasurementInputDiscountRateMember us-gaap:CommercialPortfolioSegmentMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:WeightedAverageMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:CollateralDependentImpairedLoansMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember 2025-12-31 0000707179 onb:CollateralDependentImpairedLoansMember us-gaap:MeasurementInputDiscountRateMember us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:MinimumMember 2025-12-31 0000707179 onb:CollateralDependentImpairedLoansMember us-gaap:MeasurementInputDiscountRateMember us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:MaximumMember 2025-12-31 0000707179 onb:CollateralDependentImpairedLoansMember us-gaap:MeasurementInputDiscountRateMember us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:WeightedAverageMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:ForeclosedAssetsMember us-gaap:FairValueInputsLevel3Member onb:ValuationTechniqueFairValueOfCollateralMember 2025-12-31 0000707179 onb:ForeclosedAssetsMember us-gaap:MeasurementInputDiscountRateMember us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FairValueInputsLevel3Member onb:ValuationTechniqueFairValueOfCollateralMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:ForeclosedAssetsMember us-gaap:FairValueInputsLevel3Member onb:ValuationTechniqueFairValueOfCollateralMember 2025-12-31 0000707179 onb:ForeclosedAssetsMember us-gaap:MeasurementInputDiscountRateMember us-gaap:ResidentialPortfolioSegmentMember us-gaap:FairValueInputsLevel3Member onb:ValuationTechniqueFairValueOfCollateralMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember onb:CollateralDependentImpairedLoansMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember 2024-12-31 0000707179 onb:CollateralDependentImpairedLoansMember us-gaap:MeasurementInputDiscountRateMember us-gaap:CommercialPortfolioSegmentMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:MinimumMember 2024-12-31 0000707179 onb:CollateralDependentImpairedLoansMember us-gaap:MeasurementInputDiscountRateMember us-gaap:CommercialPortfolioSegmentMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:MaximumMember 2024-12-31 0000707179 onb:CollateralDependentImpairedLoansMember us-gaap:MeasurementInputDiscountRateMember us-gaap:CommercialPortfolioSegmentMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:WeightedAverageMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:CollateralDependentImpairedLoansMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember 2024-12-31 0000707179 onb:CollateralDependentImpairedLoansMember us-gaap:MeasurementInputDiscountRateMember us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:MinimumMember 2024-12-31 0000707179 onb:CollateralDependentImpairedLoansMember us-gaap:MeasurementInputDiscountRateMember us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:MaximumMember 2024-12-31 0000707179 onb:CollateralDependentImpairedLoansMember us-gaap:MeasurementInputDiscountRateMember us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FairValueInputsLevel3Member us-gaap:ValuationTechniqueDiscountedCashFlowMember srt:WeightedAverageMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember onb:ForeclosedAssetsMember us-gaap:FairValueInputsLevel3Member onb:ValuationTechniqueFairValueOfCollateralMember 2024-12-31 0000707179 onb:ForeclosedAssetsMember us-gaap:MeasurementInputDiscountRateMember us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:FairValueInputsLevel3Member onb:ValuationTechniqueFairValueOfCollateralMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember onb:ForeclosedAssetsMember us-gaap:FairValueInputsLevel3Member onb:ValuationTechniqueFairValueOfCollateralMember 2024-12-31 0000707179 onb:ForeclosedAssetsMember us-gaap:MeasurementInputDiscountRateMember us-gaap:ResidentialPortfolioSegmentMember us-gaap:FairValueInputsLevel3Member onb:ValuationTechniqueFairValueOfCollateralMember 2024-12-31 0000707179 onb:LoansHeldForSaleMember 2025-12-31 0000707179 onb:LoansHeldForSaleMember 2024-12-31 0000707179 onb:LoansHeldForSaleMember 2025-01-01 2025-12-31 0000707179 onb:LoansHeldForSaleMember 2024-01-01 2024-12-31 0000707179 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2025-12-31 0000707179 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2025-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2025-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2025-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:ConsumerPortfolioSegmentMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2025-12-31 0000707179 us-gaap:ConsumerPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2025-12-31 0000707179 us-gaap:ConsumerPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2025-12-31 0000707179 us-gaap:ConsumerPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2025-12-31 0000707179 us-gaap:CarryingReportedAmountFairValueDisclosureMember 2024-12-31 0000707179 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2024-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:USGovernmentSponsoredEnterprisesDebtSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2024-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:MortgageBackedSecuritiesMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2024-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:USStatesAndPoliticalSubdivisionsMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:CommercialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:CommercialRealEstatePortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:ResidentialPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 us-gaap:ConsumerPortfolioSegmentMember us-gaap:CarryingReportedAmountFairValueDisclosureMember 2024-12-31 0000707179 us-gaap:ConsumerPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel1Member 2024-12-31 0000707179 us-gaap:ConsumerPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel2Member 2024-12-31 0000707179 us-gaap:ConsumerPortfolioSegmentMember us-gaap:EstimateOfFairValueFairValueDisclosureMember us-gaap:FairValueInputsLevel3Member 2024-12-31 0000707179 onb:VariableInterestRateSwapBorrowingsMember us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:CashFlowHedgingMember 2025-12-31 0000707179 onb:VariableInterestRateSwapBorrowingsMember us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:CashFlowHedgingMember 2024-12-31 0000707179 onb:VariableInterestRateSwapsCollarsAndFloorsMember us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:CashFlowHedgingMember 2025-12-31 0000707179 onb:VariableInterestRateSwapsCollarsAndFloorsMember us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:CashFlowHedgingMember 2024-12-31 0000707179 onb:VariableInterestRateSwapBorrowingsMember us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:FairValueHedgingMember 2024-12-31 0000707179 onb:VariableInterestRateSwapBorrowingsMember us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:FairValueHedgingMember 2025-12-31 0000707179 onb:VariableInterestRateSwapAvailableForSaleInvestmentSecuritiesMember us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:FairValueHedgingMember 2024-12-31 0000707179 onb:VariableInterestRateSwapAvailableForSaleInvestmentSecuritiesMember us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:FairValueHedgingMember 2025-12-31 0000707179 onb:VariableInterestRateCollarsAndFloorsMember us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:CashFlowHedgingMember 2025-12-31 0000707179 onb:VariableInterestRateCollarsAndFloorsMember us-gaap:DesignatedAsHedgingInstrumentMember us-gaap:CashFlowHedgingMember 2024-12-31 0000707179 us-gaap:DesignatedAsHedgingInstrumentMember 2025-12-31 0000707179 us-gaap:DesignatedAsHedgingInstrumentMember 2024-12-31 0000707179 onb:VariableInterestRateSwapBorrowingsMember us-gaap:FairValueHedgingMember 2025-01-01 2025-12-31 0000707179 onb:VariableInterestRateSwapAvailableForSaleInvestmentSecuritiesMember us-gaap:FairValueHedgingMember 2025-01-01 2025-12-31 0000707179 us-gaap:FairValueHedgingMember 2025-01-01 2025-12-31 0000707179 onb:VariableInterestRateSwapBorrowingsMember us-gaap:FairValueHedgingMember 2024-01-01 2024-12-31 0000707179 onb:VariableInterestRateSwapAvailableForSaleInvestmentSecuritiesMember us-gaap:FairValueHedgingMember 2024-01-01 2024-12-31 0000707179 us-gaap:FairValueHedgingMember 2024-01-01 2024-12-31 0000707179 onb:VariableInterestRateSwapBorrowingsMember us-gaap:FairValueHedgingMember 2023-01-01 2023-12-31 0000707179 onb:VariableInterestRateSwapAvailableForSaleInvestmentSecuritiesMember us-gaap:FairValueHedgingMember 2023-01-01 2023-12-31 0000707179 us-gaap:FairValueHedgingMember 2023-01-01 2023-12-31 0000707179 us-gaap:InterestRateContractMember 2025-01-01 2025-12-31 0000707179 us-gaap:InterestRateContractMember 2024-01-01 2024-12-31 0000707179 us-gaap:InterestRateContractMember 2023-01-01 2023-12-31 0000707179 us-gaap:InterestRateLockCommitmentsMember us-gaap:NondesignatedMember 2025-12-31 0000707179 onb:ForwardCommitmentsMember us-gaap:NondesignatedMember 2025-12-31 0000707179 us-gaap:InterestRateLockCommitmentsMember us-gaap:NondesignatedMember 2024-12-31 0000707179 onb:ForwardCommitmentsMember us-gaap:NondesignatedMember 2024-12-31 0000707179 onb:OffsettingCounterPartyDerivativeInstrumentMember us-gaap:NondesignatedMember 2025-12-31 0000707179 onb:CustomerDerivativeInstrumentMember us-gaap:NondesignatedMember 2025-12-31 0000707179 onb:OffsettingCounterPartyDerivativeInstrumentMember us-gaap:NondesignatedMember 2024-12-31 0000707179 onb:CustomerDerivativeInstrumentMember us-gaap:NondesignatedMember 2024-12-31 0000707179 onb:CustomerForeignExchangeForwardMember us-gaap:NondesignatedMember 2025-12-31 0000707179 onb:CustomerForeignExchangeForwardMember us-gaap:NondesignatedMember 2024-12-31 0000707179 onb:CounterpartyForeignExchangeForwardMember us-gaap:NondesignatedMember 2025-12-31 0000707179 onb:CounterpartyForeignExchangeForwardMember us-gaap:NondesignatedMember 2024-12-31 0000707179 us-gaap:NondesignatedMember 2025-12-31 0000707179 us-gaap:NondesignatedMember 2024-12-31 0000707179 us-gaap:InterestRateContractMember us-gaap:NondesignatedMember 2025-01-01 2025-12-31 0000707179 us-gaap:InterestRateContractMember us-gaap:NondesignatedMember 2024-01-01 2024-12-31 0000707179 us-gaap:InterestRateContractMember us-gaap:NondesignatedMember 2023-01-01 2023-12-31 0000707179 onb:MortgageContractMember us-gaap:NondesignatedMember 2025-01-01 2025-12-31 0000707179 onb:MortgageContractMember us-gaap:NondesignatedMember 2024-01-01 2024-12-31 0000707179 onb:MortgageContractMember us-gaap:NondesignatedMember 2023-01-01 2023-12-31 0000707179 us-gaap:ForeignExchangeContractMember us-gaap:NondesignatedMember 2025-01-01 2025-12-31 0000707179 us-gaap:ForeignExchangeContractMember us-gaap:NondesignatedMember 2024-01-01 2024-12-31 0000707179 us-gaap:ForeignExchangeContractMember us-gaap:NondesignatedMember 2023-01-01 2023-12-31 0000707179 us-gaap:NondesignatedMember 2025-01-01 2025-12-31 0000707179 us-gaap:NondesignatedMember 2024-01-01 2024-12-31 0000707179 us-gaap:NondesignatedMember 2023-01-01 2023-12-31 0000707179 us-gaap:InterestRateSwapMember 2025-12-31 0000707179 us-gaap:InterestRateSwapMember 2024-12-31 0000707179 onb:VisaIncMember 2023-12-31 0000707179 onb:VisaIncMember 2023-10-01 2023-12-31 0000707179 srt:ParentCompanyMember 2025-12-31 0000707179 onb:OldNationalBankMember 2025-12-31 0000707179 srt:ParentCompanyMember 2024-12-31 0000707179 onb:OldNationalBankMember 2024-12-31 0000707179 us-gaap:InvestmentAffiliatedIssuerMember srt:ParentCompanyMember 2025-01-01 2025-12-31 0000707179 us-gaap:InvestmentAffiliatedIssuerMember srt:ParentCompanyMember 2024-01-01 2024-12-31 0000707179 us-gaap:InvestmentAffiliatedIssuerMember srt:ParentCompanyMember 2023-01-01 2023-12-31 0000707179 srt:ParentCompanyMember 2023-12-31 0000707179 srt:ParentCompanyMember 2022-12-31 0000707179 2025-10-01 2025-12-31

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 10-K
☑      ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the fiscal year ended December 31 , 2025
or
☐      TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the transition period from ____________ to ____________
Commission File Number 001-15817
Old National Bancorp
(Exact name of the Registrant as specified in its charter)

Indiana 35-1539838
(State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.)

One Main Street 47708
Evansville, Indiana
(Address of principal executive offices) (Zip Code)

( 800 ) 731-2265
(Registrant's telephone number, including area code)
Securities registered pursuant to Section 12(b) of the Act:  

Title of each class Trading
Symbol(s) Name of each exchange on which registered
Common stock, no par value ONB NASDAQ Global Select Market
Depositary Shares, each representing a 1/40th interest in a share of Non-Cumulative Perpetual Preferred Stock, Series A ONBPP NASDAQ Global Select Market
Depositary Shares, each representing a 1/40th interest in a share of Non-Cumulative Perpetual Preferred Stock, Series C ONBPO NASDAQ Global Select Market

Securities registered pursuant to Section 12(g) of the Act: None
Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☑ No ☐
Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. Yes ☐ No ☑
Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☑ No ☐
Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes ☑ No ☐
Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer ☑
Accelerated filer ☐

Non-accelerated filer ☐
Smaller reporting company ☐

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐
Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☑
If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐
Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐
Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No ☑
The aggregate market value of the registrant’s voting and non-voting common stock held by non-affiliates on June 30, 2025, was $ 8,296,882,698 (based on the closing price on that date of $21.34). In calculating the market value of securities held by non-affiliates of the registrant, the registrant has treated as securities held by affiliates as of June 30, 2025, voting and non-voting stock owned of record by its directors and principal executive officers, and voting and non-voting stock held by the registrant's trust department in a fiduciary capacity for benefit of its directors and principal executive officers. This calculation does not reflect a determination that persons are affiliates for any other purposes.
The number of shares outstanding of the registrant’s common stock, as of January 31, 2026, was 389,673,000 .
DOCUMENTS INCORPORATED BY REFERENCE
Portions of the Proxy Statement for the 2026 Annual Meeting of Shareholders are incorporated by reference into Part III of this Form 10-K.

OLD NATIONAL BANCORP
2025 ANNUAL REPORT ON FORM 10-K
TABLE OF CONTENTS

Page
PART I
Item 1. Business
5

Item 1A. Risk Factors
16

Item 1B. Unresolved Staff Comments
31

Item 1C. Cybersecurity
31

Item 2. Properties
33

Item 3. Legal Proceedings
33

Item 4. Mine Safety Disclosures
33

PART II
Item 5. Market for the Registrant's Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities
34

Item 6. [Reserved]
35

Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations
36

Item 7A. Quantitative and Qualitative Disclosures About Market Risk
68

Item 8. Financial Statements and Supplementary Data
69

Item 9. Changes in and Disagreements with Accountants on Accounting and Financial Disclosure
136

Item 9A. Controls and Procedures
136

Item 9B. Other Information
138

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections
138

PART III
Item 10. Directors, Executive Officers and Corporate Governance
139

Item 11. Executive Compensation
140

Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters
140

Item 13. Certain Relationships and Related Transactions, and Director Independence
140

Item 14. Principal Accounting Fees and Services
141

PART IV
Item 15. Exhibits and Financial Statement Schedules
142

Item 16. Form 10-K Summary
145

SIGNATURES
146

2

OLD NATIONAL BANCORP
2025 ANNUAL REPORT ON FORM 10-K
GLOSSARY OF ABBREVIATIONS AND ACRONYMS

As used in this report, references to “Old National,” “the Company,” “we,” “our,” “us,” and similar terms refer to the consolidated entity consisting of Old National Bancorp and its wholly owned subsidiaries. Old National Bancorp refers solely to the parent holding company, and Old National Bank refers to Old National Bancorp’s bank subsidiary.

The acronyms and abbreviations identified below are used throughout this report, including the Notes to Consolidated Financial Statements. You may find it helpful to refer to this page as you read this report.

ACH:  Automated Clearing House
AOCI:  accumulated other comprehensive income (loss)
AQR:  asset quality rating
ASC:  Accounting Standards Codification
ASU:  Accounting Standards Update
ATM:  automated teller machine
BBCC: business banking credit center (small business)
Bremer: Bremer Financial Corporation
CapStar:  CapStar Financial Holdings, Inc.
CECL:  current expected credit loss
CFPB:  Consumer Financial Protection Bureau
Common Stock:  Old National Bancorp common stock, no par value
DTI:  debt-to-income
ESG: environmental, social, and governance
FASB:  Financial Accounting Standards Board
FDIC:  Federal Deposit Insurance Corporation
FHLB:  Federal Home Loan Bank
FHLBI:  Federal Home Loan Bank of Indianapolis
FHTC:  Federal Historic Tax Credit
FICO:  Fair Isaac Corporation
First Midwest: First Midwest Bancorp, Inc.
GAAP:  U.S. generally accepted accounting principles
IDI: insured depository institution
LGD:  loss given default
LIBOR:  London Interbank Offered Rate
LIHTC:  Low Income Housing Tax Credit
LTV:  loan-to-value
Merger: merger between Old National and Bremer
N/A:  not applicable
N/M:  not meaningful
NASDAQ:  NASDAQ Global Select Market
NMTC: New Markets Tax Credit
NOW:  negotiable order of withdrawal
OCC:  Office of the Comptroller of the Currency
PCD:  purchased credit deteriorated
PD:  probability of default
Preferred Stock:  Old National Bancorp preferred stock
Renewable Energy:  investment tax credits for solar projects
SEC:  U.S. Securities and Exchange Commission
SOFR: Secured Overnight Financing Rate
3

OLD NATIONAL BANCORP
2025 ANNUAL REPORT ON FORM 10-K
FORWARD-LOOKING STATEMENTS
This report contains certain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995 (the “Act”), Section 27A of the Securities Act of 1933 and Rule 175 promulgated thereunder, and Section 21E of the Securities Exchange Act of 1934 and Rule 3b-6 promulgated thereunder, notwithstanding that such statements are not specifically identified as such. In addition, certain statements may be contained in our future filings with the SEC, in press releases, and in oral and written statements made by us that are not statements of historical fact and constitute forward‐looking statements within the meaning of the Act. These statements include, but are not limited to, descriptions of Old National’s financial condition, results of operations, asset and credit quality trends, profitability and business plans or opportunities. Forward-looking statements can be identified by the use of words such as “anticipate,” “believe,” “contemplate,” “continue,” “could,” “estimate,” “expect,” “guidance,” “intend,” “may,” “outlook,” “plan,” “potential,” “predict,” “should,” “would,” and “will,” and other words of similar meaning. These forward-looking statements express management’s current expectations or forecasts of future events and, by their nature, are subject to risks and uncertainties. There are a number of factors that could cause actual results or outcomes to differ materially from those in such statements, including, but not limited to: competition; government legislation, regulations and policies, including trade and tariff policies; the ability of Old National to execute its business plan; unanticipated changes in our liquidity position, including but not limited to changes in our access to sources of liquidity and capital to address our liquidity needs; changes in economic conditions and economic and business uncertainty which could materially impact credit quality trends and the ability to generate loans and gather deposits; inflation and governmental responses to inflation, including increasing interest rates; market, economic, operational, liquidity, credit, and interest rate risks associated with our business; our ability to successfully manage our credit risk and the sufficiency of our allowance for credit losses; the expected cost savings, synergies and other financial benefits from the Merger between Old National and Bremer not being realized within the expected time frames and costs or difficulties relating to integration matters being greater than expected; potential adverse reactions or changes to business or employee relationships, including those resulting from the completion of the Merger; the impact of purchase accounting with respect to the Merger, or any change in the assumptions used regarding the assets acquired and liabilities assumed to determine their fair value and credit marks; the potential impact of future business combinations on our performance and financial condition, including our ability to successfully integrate the businesses, the success of revenue-generating and cost reduction initiatives and the diversion of management’s attention from ongoing business operations and opportunities; failure or circumvention of our internal controls; operational risks or risk management failures by us or critical third parties, including without limitation with respect to data processing, information technology systems, cybersecurity, technological changes, vendor issues, business interruption, and fraud risks; significant changes in accounting, tax or regulatory practices or requirements; new legal obligations or liabilities; disruptive technologies in payment systems and other services traditionally provided by banks; adverse effects on our information technology systems, or those of third parties, resulting from failures, disruptions or cybersecurity attacks, including ransomware; security breaches, including denial of service attacks, hacking, social engineering attacks, malware intrusion and other cybersecurity threats; the effects of climate change on Old National and its customers, borrowers, or service providers; political and economic uncertainty and instability; the impacts of pandemics, epidemics and other infectious disease outbreaks; other matters discussed in this report; and other factors identified in filings with the SEC. These forward-looking statements are made only as of the date of this report and are not guarantees of future results, performance, or outcomes.
Such forward-looking statements are based on assumptions and estimates, which although believed to be reasonable, may turn out to be incorrect. Therefore, undue reliance should not be placed upon these estimates and statements. We cannot assure that any of these statements, estimates, or beliefs will be realized and actual results or outcomes may differ from those contemplated in these forward-looking statements. Old National does not undertake an obligation to update these forward-looking statements to reflect events or conditions after the date of this report. You are advised to consult further disclosures we may make on related subjects in our filings with the SEC.
Investors should consider these risks, uncertainties, and other factors in addition to the factors under the heading “Risk Factors” included in this filing and our other filings with the SEC.
4

PART I

ITEM 1.    BUSINESS
COMPANY PROFILE
Old National Bancorp, the financial holding company of Old National Bank, our wholly owned banking subsidiary (“Old National Bank”), is incorporated in the state of Indiana, is the sixth largest Midwestern-headquartered bank by asset size with consolidated assets of $72.2 billion at December 31, 2025, and ranks among the top 25 banking companies headquartered in the United States. The Company’s corporate headquarters and principal executive office are located in Evansville, Indiana with commercial and consumer banking operations headquartered in Chicago, Illinois. Through Old National Bank and our non-bank affiliates, we provide a wide range of services primarily throughout the Midwest and Southeast regions of the United States. In addition to providing extensive services in consumer and commercial banking, Old National offers comprehensive wealth management and capital markets services.
THE BANK
Old National Bank traces its roots to 1834 and at December 31, 2025, operated 346 banking centers located primarily throughout the Midwestern and Southeastern United States, including Illinois, Indiana, Iowa, Kentucky, Michigan, Minnesota, North Carolina, North Dakota, Tennessee, and Wisconsin. Each of the banking centers of Old National Bank provides a group of similar community banking services, including such products and services as commercial, real estate, and consumer loans; deposits; and private banking, capital markets, brokerage, wealth management, trust, and investment advisory services.
We earn interest income on loans as well as fee income from the origination of loans and from providing other services to our clients. Lending activities include loans to individuals, which primarily consist of home equity lines of credit, residential real estate loans, and consumer loans, and loans to commercial clients, which include commercial loans, commercial real estate loans, agricultural loans, letters of credit, and lease financing. Residential real estate loans are either kept in our loan portfolio or sold to secondary investors.
We strive to serve individuals and commercial clients by providing depository services that fit their needs at competitive rates. We pay interest on interest-bearing deposits and receive service fee revenue on various accounts. Deposit accounts include products such as noninterest-bearing demand, interest-bearing checking and NOW, savings and money market, and time deposits. Debit and ATM cards provide clients with access to their accounts 24 hours a day at any ATM location. We also provide 24-hour telephone access and online banking as well as other electronic and mobile banking services.
In addition to providing lending and deposit services, we offer comprehensive wealth management, trust, investment advisory, brokerage, and foreign currency services. For businesses, we provide treasury management, merchant, and capital markets services as well as community development lending and equity investment solutions intended to produce jobs and revitalize our communities.
HUMAN CAPITAL RESOURCES
At December 31, 2025, we employed 4,971 full‑time equivalent team members. Attracting, developing, and retaining top talent is a strategic priority supported by integrated talent and succession planning, structured hiring practices, comprehensive total rewards, and meaningful growth opportunities. We provide professional development programs—including career skills training, peer mentoring, and opportunities to engage with senior leaders—along with structured leadership development programs, associate and community engagement teams, impact networks, and other learning and development programs to support team member development, engagement, and job satisfaction.
Old National provides a competitive total rewards package that includes base pay, incentive opportunities, and comprehensive benefits. Our benefits package includes health insurance and wellness coverages, a retirement plan with company matching contributions, other welfare plan coverages, paid time off, and paid leave benefits. To support team member health and well‑being, Old National offers medical programs designed to enhance access to quality care. Team members have access to mental well‑being resources, including mindfulness tools and traditional Employee Assistance Program services. Our medical benefits also include specialized support for complex health conditions, such as access to nationally recognized centers of excellence and condition‑specific care solutions.
5

Additionally, team members in certain areas have access to employer‑sponsored healthcare clinics that provide convenient primary and preventive care.
Old National team members consistently strive to make a positive difference in the communities we serve, sharing their talents through volunteer activities in education, economic development, human and health services, and community reinvestment. We offer a program that allows each team member to be paid up to 24 hours per year to volunteer for activities in their community during normal work hours. Under that program, team members logged approximately 67,700 volunteer hours during 2025 in support of nearly 2,700 organizations, and team members with 25 hours or more of service each year are recognized annually by executive management.
AREAS SERVED
Since our founding, Old National has focused on community and commercial banking by building long-term, highly valued partnerships with our clients. We have continued to expand our footprint in the Midwest and Southeast regions through strategic mergers and acquisitions, and we are now the sixth largest bank headquartered in the Midwest by assets.
The following table reflects information on the top areas we currently serve.

Metropolitan Statistical Area Deposits as a
Percent of
Old
National
Bank
Franchise
(%) Deposits
Per
Branch
($M) 2020-2026
Population
Change
(%) 2026-2031
Projected
Population
Change
(%) 2026
Median
Household
Income
($) 2026-2031
Projected
Household
Income
Change
(%)
Chicago-Naperville-Elgin, IL-IN-WI 32.8  202.4  (0.2) 0.5  97,107  13.1 
Minneapolis-St. Paul-Bloomington, MN-WI 15.0  182.7  2.6  2.3  105,075  10.6 
Evansville, IN 9.9  363.7  0.9  0.6  74,892  12.3 
Indianapolis-Carmel-Anderson, IN 4.1  108.0  5.3  3.4  87,303  11.8 
Milwaukee-Waukesha, WI 2.5  227.2  (0.1) 0.2  84,352  12.3 
Madison, WI 2.2  108.4  5.3  3.8  81,438  7.9 

National average 3.5   2.6   86,867   11.3  
Weighted average total Old National Bank 1.2   1.1   88,447   11.3  

Source: S&P Global Market Intelligence. Deposit data as of June 30, 2025.
STRATEGIC TRANSACTIONS
Since forming our holding company in 1982, we have acquired over 50 financial institutions and other financial services businesses. Old National assesses possible mergers, acquisitions, and divestitures based on a disciplined financial evaluation process and expects that future mergers, acquisitions, and divestitures will be consistent with our existing basic banking strategy, which focuses on community banking, client relationships, and consistent quality earnings. Targeted geographic markets for mergers and acquisitions include markets with average to above average growth rates within our general footprint.
We anticipate that, as with previous mergers and acquisitions, the consideration paid by us in future mergers and acquisitions may be principally in the form of cash and/or Old National stock, or a combination thereof, and may reflect a premium to the target’s then-market value. The amount and structure of such consideration is based on reasonable growth and cost savings assumptions and a thorough analysis of the impact on both long- and short-term financial results.
Our ability to engage in certain transactions depends on the bank regulators’ views at the time as to the capital levels, quality of management, and overall condition of Old National, in addition to their assessment of a variety of other factors, including our compliance with law and regulations.
On April 1, 2024, Old National completed its acquisition of CapStar and its wholly owned subsidiary, CapStar Bank, in an all-stock transaction. This partnership strengthened Old National’s Nashville, Tennessee presence and added several new high-growth markets. At closing, CapStar contributed $3.1 billion in total assets, $2.1 billion in total loans, and $2.6 billion in total deposits.
On May 1, 2025, Old National completed its acquisition of Bremer and its wholly owned subsidiary, Bremer Bank, National Association. At closing, Bremer contributed approximately $16.3 billion of total assets, $11.1 billion of
6

total loans, and $12.9 billion of deposits. This partnership solidified our position in Minnesota while adding attractive funding in North Dakota.
COMPETITION
The banking industry and related financial service providers operate in a highly competitive market. Old National competes with financial service providers such as other commercial banks, savings and loan associations, credit unions, mortgage banking firms, financial technology, or “FinTech,” companies, consumer finance companies, securities brokerage firms, insurance companies, money market mutual funds, private equity and debt funds, and other financial services providers.
Many of our competitors are financial institutions that are larger than we are and have substantially greater resources than we do. Some of our nonfinancial institution competitors may have fewer regulatory constraints, broader geographic service areas, greater capital, and, in some cases, lower cost structures. In addition, competition for clients has intensified as a result of changes in regulation, mergers and acquisitions, advances in technology and product delivery systems, and consolidation among financial service providers.
SUPERVISION AND REGULATION
Old National is subject to extensive and comprehensive regulation under federal and state laws. The regulatory framework is intended primarily for the protection of depositors, federal deposit insurance funds, and the banking system as a whole and not for the protection of shareholders or non-depository creditors.
Significant elements of certain laws and regulations applicable to Old National and its subsidiaries are described below. Applicable statutes, regulations, and policies are continually under review by Congress and state legislatures and federal and state regulatory agencies and are subject to change. Old National is unable to predict changes in applicable laws or regulations, or in their interpretation and application by regulatory agencies and other governmental authorities, and any such change could have a material effect on our business.
Old National Bancorp is registered as a bank holding company and has elected to be a financial holding company under the Bank Holding Company Act of 1956, as amended (the “BHC Act”). As a bank holding company and financial holding company, Old National Bancorp is subject to supervision, examination, and regulation by the Board of Governors of the Federal Reserve System (the “Federal Reserve”) under the BHC Act, and is required to file reports with the Federal Reserve and to provide the Federal Reserve any additional information it may require. As a national bank, Old National Bank is subject to primary regulation, supervision, and examination by the OCC.
Bank Holding Company Regulation. Generally, the BHC Act governs the acquisition and control of banks and non-banking companies by bank holding companies. The BHC Act also regulates the business activities of bank holding companies and their non-bank subsidiaries.
The BHC Act, the Bank Merger Act, and other federal and state statutes regulate acquisitions of commercial banks and their holding companies. The BHC Act requires the prior approval of the Federal Reserve for the direct or indirect acquisition by a bank holding company of more than 5.0% of the voting shares of a commercial bank or its holding company. Under the BHC Act and the Bank Merger Act, the prior approval of the Federal Reserve or other appropriate bank regulatory authority is required for a bank holding company to acquire control of another bank or for a bank to merge with another bank or purchase the assets or assume the deposits of another bank. In reviewing applications seeking approval of merger and acquisition transactions, the bank regulatory authorities will consider, among other things, the competitive effect and public benefits of the transactions, the capital position of the combined organization, the risks to the stability of the U.S. banking or financial system, the applicant’s managerial and financial resources, the applicant’s performance record under the Community Reinvestment Act of 1977, as amended (the “CRA”) and its compliance with law, including fair housing laws and other consumer protection laws, and the effectiveness of the subject organizations in combating money laundering activities.
In general, the BHC Act limits the business of bank holding companies to banking, managing, or controlling banks and other activities that the Federal Reserve has determined to be so closely related to banking as to be a proper incident thereto. In addition, bank holding companies that qualify and elect to be financial holding companies may engage in any activity, or acquire and retain the shares of a company engaged in any activity, that is either (i) financial in nature or incidental to such financial activity (as determined by the Federal Reserve in consultation with the Secretary of the Treasury) or (ii) complementary to a financial activity and does not pose a substantial risk to the safety and soundness of depository institutions or the financial system generally (as solely determined by the Federal
7

Reserve), without prior approval of the Federal Reserve. Activities that are financial in nature include securities underwriting and dealing, insurance underwriting and making merchant banking investments, among others.
To maintain financial holding company status, a financial holding company and all of its depository institution subsidiaries must be “well capitalized” and “well managed.” A depository institution subsidiary is considered to be “well capitalized” if it satisfies the requirements for this status discussed in “Prompt Corrective Action” below. A depository institution subsidiary is considered “well managed” if it received a composite rating and management rating of at least “satisfactory” in its most recent examination. A financial holding company’s status will also depend upon it maintaining its status as “well capitalized” and “well managed” under applicable Federal Reserve regulations. If a financial holding company ceases to meet these capital and management requirements, the BHC Act and the Federal Reserve’s regulations provide that the financial holding company must enter into a confidential agreement with the Federal Reserve to comply with all applicable capital and management requirements. Until the financial holding company returns to compliance, the Federal Reserve may impose limitations or conditions on the conduct of its activities, and the company may not commence any of the broader financial activities permissible for financial holding companies or acquire a company engaged in such financial activities without prior approval of the Federal Reserve. If the company does not return to compliance within 180 days, the Federal Reserve may require divestiture of the holding company’s depository institutions. Bank holding companies and banks must also be both well capitalized and well managed in order to acquire banks located outside their home state.
In order for a financial holding company to commence any new activity permitted by the BHC Act or to acquire a company engaged in any new activity permitted by the BHC Act, each insured depository institution subsidiary of the financial holding company must have received a rating of at least “satisfactory” in its most recent CRA performance evaluation.
The Federal Reserve has the power to order any bank holding company or its subsidiaries to terminate any activity or to terminate its ownership or control of any subsidiary when the Federal Reserve has reasonable grounds to believe that continuation of such activity or such ownership or control constitutes a serious risk to the financial soundness, safety or stability of any bank subsidiary of the bank holding company.
Source of Strength. Federal Reserve policy and regulations and federal law require bank holding companies to act as a source of financial and managerial strength to their subsidiary banks. Under this requirement, a bank holding company is expected to commit financial resources to support its bank subsidiary even at times when the holding company may not be in a financial position to provide such resources or when the holding company may not be inclined to provide it. Any loans by a bank holding company to its subsidiary bank are subordinate in right of payment to deposits and to certain other indebtedness of such subsidiary bank. In the event of a bank holding company’s bankruptcy, any commitment by the bank holding company to a federal bank regulatory agency to maintain the capital of a bank subsidiary will be assumed by the bankruptcy trustee and entitled to priority of payment.
Financial Privacy. Under the Gramm-Leach-Bliley Act of 1999 (the “GLB Act”), a financial institution may not disclose non-public personal information about a consumer to unaffiliated third parties unless the institution satisfies various disclosure requirements, and the consumer has not elected to opt out of the information sharing. The financial institution must provide its clients with a notice of its privacy policies and practices. The Federal Reserve, the FDIC, and other financial regulatory agencies issued regulations implementing notice requirements and restrictions on a financial institution’s ability to disclose non-public personal information about consumers to unaffiliated third parties.
In addition, privacy and data protection are areas of increasing state legislative focus, and a number of states have enacted consumer privacy laws that impose significant compliance obligations with respect to personal information. Similar laws may in the future be adopted by states where the Company and Old National Bank do business. Furthermore, privacy and data protection areas are expected to receive additional attention at the Federal level. The potential effects of state or Federal privacy and data protection laws on the Company’s business cannot be determined at this time and will depend both on whether such laws are adopted by states in which the Company does business and/or at the Federal level and the requirements imposed by any such laws.
Bank Secrecy Act and the USA Patriot Act. The U.S. Bank Secrecy Act (the “BSA”) and USA PATRIOT Act require financial institutions to develop programs to prevent them from being used for, and to detect and deter, money laundering, terrorist financing, and other illegal activities. If such activities are detected or suspected, financial institutions are obligated to file suspicious activity reports with the U.S. Treasury’s Office of Financial Crimes Enforcement Network. These rules require financial institutions to establish procedures for identifying and
8

verifying the identity of clients seeking to open new accounts and monitoring these accounts on an ongoing basis to ensure that such accounts are not used for illegal purposes. Failure to comply with these requirements could have serious financial, legal, and reputational consequences, including the imposition of civil money penalties, cease and desist orders, or causing applicable bank regulatory authorities not to approve merger or acquisition transactions or to prohibit transactions even if approval is not required.
Office of Foreign Assets Control Regulation. The U.S. imposes economic sanctions that affect transactions with designated foreign countries, nationals, and others. These sanctions are administered by the U.S. Treasury’s Office of Foreign Assets Control (“OFAC”). These sanctions include: (i) restrictions on trade with or investment in a sanctioned country, including prohibitions against direct or indirect imports from and exports to a sanctioned country and prohibitions on “U.S. persons” engaging in financial transactions relating to making investments in, or providing investment-related advice or assistance to, a sanctioned country, and (ii) blocking assets in which the government or specially designated nationals of the sanctioned country have an interest by prohibiting transfers of property subject to U.S. jurisdiction (including property in the possession or control of U.S. persons). Blocked assets (e.g., property and bank deposits) cannot be paid out, withdrawn, set off, or transferred in any manner without a license from OFAC. Failure to comply with these sanctions could have serious financial, legal, and reputational consequences for the institution, including the imposition of civil money penalties, or causing applicable bank regulatory authorities not to approve merger or acquisition transactions.
Consumer Financial Protection. Old National Bank is subject to laws designed to protect consumers and prohibit unfair or deceptive business practices, including the Equal Credit Opportunity Act, the Fair Housing Act, the Home Ownership Protection Act, the Fair Credit Reporting Act, as amended by the Fair and Accurate Credit Transactions Act of 2003 (“FACT Act”), the GLB Act, the Truth in Lending Act, the CRA, the Home Mortgage Disclosure Act, the Real Estate Settlement Procedures Act, the National Flood Insurance Act and applicable state law counterparts. T hese and other laws, among other things, require disclosures of the cost of credit and terms of deposit accounts, provide substantive consumer rights, prohibit discrimination in credit transactions, regulate the use of credit report information, provide financial privacy protections, prohibit unfair, deceptive, and abusive practices and subject us to substantial regulatory oversight. Violations of applicable consumer protection laws can result in reputational damage and potential liability from litigation brought by customers, including actual damages, restitution, and attorneys’ fees. Federal bank regulators, state attorneys general and state and local consumer protection agencies may also seek to enforce consumer protection requirements and obtain these and other remedies, including regulatory sanctions, customer rescission rights, action by the state and local attorneys general in each jurisdiction in which we operate and civil money penalties. Failure to comply with consumer protection requirements may also result in failure to obtain any required bank regulatory approval for merger or acquisition transactions or prohibit such transactions even if approval is not required.
In addition, the CFPB has a broad mandate to prohibit unfair, deceptive, or abusive acts and practices, is specifically empowered to require certain disclosures to consumers and draft model disclosure forms and is responsible for making rules and regulations under the federal consumer protection laws relating to financial products and services. The CFPB has examination and enforcement authority over all banks with more than $10 billion in assets, as well as their affiliates, and can issue cease-and-desist orders against banks and other entities that violate consumer financial laws. The CFPB may also institute a civil action against an entity in violation of federal consumer financial laws in order to impose a civil money penalty or injunction.
On October 22, 2024, the CFPB finalized a new rule that requires a provider of payment accounts or products, such as a bank, to make data available to consumers upon request regarding the products or services they obtain from the provider. Any such data provider also has to make such data available to third parties, with the consumer’s express authorization and through an interface that satisfies formatting, performance and security standards, for the purpose of such third parties providing the consumer with financial products or services requested by the consumer. Data required to be made available under the rule includes transaction information, account balance, account and routing numbers, terms and conditions, upcoming bill information, and certain account verification data. The rule is intended to give consumers control over their financial data, including with whom it is shared, and encourage competition in the provision of consumer financial products or services. For banks with at least $10 billion and less than $250 billion in total assets, which currently includes Old National Bank, compliance with the rule’s requirements is required beginning on April 1, 2027. The rule is the subject of litigation, which is currently stayed while the CFPB considers revisions to the rule.
During 2025, the CFPB initiated a reduction of its staff by over 80%. The reduction in force is the subject of litigation, and the staffing cuts are currently stayed pending federal court en banc rehearing of the case. The resulting
9

impact of these developments on our business is uncertain at this time. State regulators and state attorneys general may increase regulatory, investigative, and enforcement activity with respect to consumer protection, in response to changes in regulation, supervision, and enforcement of consumer protection laws by federal regulators.
Interchange Fees. Old National Bank is subject to interchange fee limitations that establish a maximum permissible interchange fee for many types of debit interchange transactions that is equal to no more than 21 cents per transaction plus five basis points multiplied by the value of the transaction. Interchange fees, or “swipe” fees, are charges that merchants pay to card-issuing banks, such as Old National Bank, for processing electronic payment transactions. Additional Federal Reserve rules allow a debit card issuer to recover one cent per transaction for fraud prevention purposes if the issuer complies with certain fraud-related requirements.
On October 25, 2023, the Federal Reserve proposed amendments to its rules on interchange fees. The proposed changes would establish a maximum permissible interchange fee of no more than 14.4 cents per transaction plus four basis points multiplied by the value of the transaction. The fraud prevention adjustment would be increased to 1.3 cents per transaction. The proposed rule would also establish an automatic update of the interchange fee cap every other year based on a survey of debit card issuers.
In June 2024, the State of Illinois adopted the Illinois Interchange Fee Prohibition Act, which restricts credit card and debit card interchange fees, as defined in the legislation, that may be charged on portions of electronic payment transactions attributable to taxes and gratuities. In December 2024, a U.S. District Court preliminarily enjoined this law from applying to national banks, including Old National Bank.
Capital Adequacy.
Capital Requirements . Old National Bancorp and Old National Bank are each required to comply with certain risk-based capital and leverage requirements under capital rules adopted by the Federal Reserve, the OCC, and the FDIC (the “Basel III Capital Rules”). These rules implement the Basel III framework set forth by the Basel Committee on Banking Supervision (the “Basel Committee”) as well as certain provisions of the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”).
The Basel III Capital Rules define qualifying capital instruments and specify minimum amounts of capital as a percentage of assets that banking organizations are required to maintain. Under the Basel III Capital Rules, risk-based capital ratios are calculated by dividing Common Equity Tier 1 (“CET1”) capital, Tier 1 capital and total risk-based capital, respectively, by risk-weighted assets. Assets and off-balance sheet credit equivalents are assigned a risk weight based primarily on supervisory assessments of relative credit risk.
Under the Basel III Capital Rules, the Company and Old National Bank are each required to maintain the following:
• A minimum ratio of CET1 to risk-weighted assets of 4.5%, plus a 2.5% “capital conservation buffer” that is composed entirely of CET1 capital (effectively resulting in a minimum ratio of CET1 to risk-weighted assets of 7.0%).
• A minimum ratio of Tier 1 capital to risk-weighted assets of 6.0%, plus the capital conservation buffer (effectively resulting in a minimum Tier 1 capital ratio of 8.5%).
• A minimum ratio of total capital (Tier 1 capital plus Tier 2 capital) to risk-weighted assets of 8.0%, plus the capital conservation buffer (effectively resulting in a minimum total capital ratio of 10.5%).
• A minimum leverage ratio of 4.0%, calculated as the ratio of Tier 1 capital to average assets.
The capital conservation buffer is designed to absorb losses during periods of economic stress. Banking institutions with a ratio of CET1 to risk-weighted assets above the minimum, but below the conservation buffer, will face constraints on dividends, equity repurchases, and compensation based on the amount of the shortfall and the institution’s “eligible retained income” (that is, the greater of (i) net income for the preceding four quarters, net of distributions and associated tax effects not reflected in net income and (ii) average net income over the preceding four quarters).
The Basel III Capital Rules also provide for a number of deductions from and adjustments to CET1 capital. As a “non-advanced approaches” firm under the Basel III Capital Rules, the Company is subject to rules that provide for simplified capital requirements relating to the threshold deductions for mortgage servicing assets, deferred tax assets arising from temporary differences that a banking organization could not realize through net operating loss carry backs, and investments in the capital of unconsolidated financial institutions, as well as the inclusion of minority interests in regulatory capital.
10

The Company and Old National Bank, as non-advanced approaches banking organizations under the Basel III Capital Rules, made a one-time permanent election to exclude the effects of certain AOCI items included in shareholders’ equity under GAAP in determining regulatory capital ratios.
In December 2017, the Basel Committee published standards that it described as the finalization of the Basel III post-crisis regulatory reforms. Among other things, these standards revise the Basel Committee’s standardized approach for credit risk (including the recalibration of risk weights and introducing new capital requirements for certain “unconditionally cancellable commitments,” such as unused credit card lines of credit) and provide a new standardized approach for operational risk capital. Under the current U.S. capital rules, operational risk capital requirements and a capital floor apply only to advanced approaches banking organizations, and therefore not to the Company or Old National Bank.
On July 27, 2023, the federal banking regulators proposed revisions to the Basel III Capital Rules to implement the Basel Committee’s 2017 standards and make other changes to the Basel III Capital Rules. The revised capital requirements of the proposed rule would not apply to the Company or Old National Bank because they have less than $100 billion in total consolidated assets and trading assets and liabilities below the threshold for market risk requirements. The federal banking regulators have indicated that they expect to issue a revised proposal.
Prompt Corrective Action . The Federal Deposit Insurance Act (the “FDIA”) requires the federal banking agencies to take “prompt corrective action” for depository institutions that do not meet the minimum capital requirements described above. The FDIA includes the following five capital categories: “well-capitalized,” “adequately capitalized,” “undercapitalized,” “significantly undercapitalized” and “critically undercapitalized.” An insured depository institution is considered:
• “Well-capitalized” if the institution has a total risk-based capital ratio of 10.0% or greater, a Tier 1 risk-based capital ratio of 8.0% or greater, a CET1 capital ratio of 6.5% or greater, and a leverage ratio of 5.0% or greater, and is not subject to any order or written directive by any such regulatory authority to meet and maintain a specific capital level for any capital measure.
• “Adequately capitalized” if the institution has a total risk-based capital ratio of 8.0% or greater, a Tier 1 risk-based capital ratio of 6.0% or greater, a CET1 capital ratio of 4.5% or greater, and a leverage ratio of 4.0% or greater and is not “well-capitalized.”
• “Undercapitalized” if the institution has a total risk-based capital ratio of less than 8.0%, a Tier 1 risk-based capital ratio of less than 6.0%, a CET1 capital ratio of less than 4.5%, or a leverage ratio of less than 4.0%.
• “Significantly undercapitalized” if the institution has a total risk-based capital ratio of less than 6.0%, a Tier 1 risk-based capital ratio of less than 4.0%, a CET1 capital ratio of less than 3.0% or a leverage ratio of less than 3.0%.
• “Critically undercapitalized” if the institution’s tangible equity is equal to or less than 2.0% of average quarterly tangible assets.
An institution may be downgraded to, or deemed to be in, a capital category that is lower than indicated by its capital ratios if it is determined to be in an unsafe or unsound condition or if it receives an unsatisfactory examination rating for certain matters. A bank’s capital category is determined solely for the purpose of applying prompt corrective action regulations, and the capital category may not constitute an accurate representation of the bank’s overall financial condition or prospects for other purposes. As of December 31, 2025, Old National Bank’s capital ratios were all in excess of the minimum requirements for “well-capitalized” status under such rules.
The federal banking regulators must take certain mandatory supervisory actions, and are authorized to take other discretionary actions, with respect to institutions that are less than adequately capitalized, with supervisory actions progressively becoming more restrictive as the institution’s capital category declines. Supervisory actions include: (i) restrictions on payment of capital distributions and management fees, (ii) requirements that a federal bank regulator monitor the condition of the institution and its efforts to restore its capital, (iii) submission of a capital restoration plan, (iv) restrictions on the growth of the institution’s assets and (v) requirements for prior regulatory approval of certain expansion proposals. A bank that is “critically undercapitalized” will be subject to further restrictions and generally will be placed in conservatorship or receivership within 90 days.
The FDIA prohibits an insured depository institution from accepting brokered deposits or offering interest rates on any deposits significantly higher than the prevailing rate in the bank’s normal market area or nationally (depending upon where the deposits are solicited), unless it is well-capitalized or is adequately capitalized and receives a waiver from the FDIC. A depository institution that is adequately capitalized and accepts brokered deposits under a waiver
11

from the FDIC may not pay an interest rate on any deposits in excess of 75 basis points over certain prevailing market areas.
The FDIA’s prompt corrective action provisions apply only to depository institutions, and not to bank holding companies. Under the Federal Reserve’s regulations, a bank holding company is considered “well capitalized” if the bank holding company (i) has a total risk based capital ratio of at least 10%, (ii) has a Tier 1 risk-based capital ratio of at least 6%, and (iii) is not subject to any written agreement order, capital directive or prompt corrective action directive to meet and maintain a specific capital level for any capital measure. Although prompt corrective action regulations apply only to depository institutions and not to bank holding companies, a bank that is required to submit a capital restoration plan generally must concurrently submit a performance guarantee by its parent holding company. The liability of the parent holding company under any such guarantee is limited to the lesser of five percent of the bank’s assets at the time it became “undercapitalized”, or the amount needed to comply.
Dividends Limitations. A substantial portion of Old National Bancorp’s revenue is derived from dividends paid to it by Old National Bank. Limitations on Old National Bancorp’s ability to receive dividends from Old National Bank could have a material adverse effect on its liquidity and ability to pay dividends on its Common Stock and Preferred Stock or interest and principal on its debt, and ability to fund purchases of its Common Stock. Under OCC regulations, national banks generally may not declare a dividend in excess of the bank’s undivided profits or, absent OCC approval, if the total amount of dividends declared by the national bank in any calendar year exceeds the total of the national bank’s retained net income year-to-date combined with its retained net income for the preceding two years. National banks also are prohibited from declaring or paying any dividend if, after making the dividend, the national bank would be considered “undercapitalized” (as defined by reference to other OCC regulations). The OCC has the authority to use its enforcement powers to prohibit a national bank, such as Old National Bank, from paying dividends if, in its opinion, the payment of dividends would constitute an unsafe or unsound practice. Further, Old National Bank’s ability to pay dividends is restricted if it does not maintain the capital conservation buffer described under “—Capital Adequacy—Capital Requirements” above.
In addition, the FDIA generally prohibits a depository institution from making any capital distributions (including payment of a dividend) or paying any management fee to its parent holding company if the depository institution would thereafter be “undercapitalized” as described under “—Capital Adequacy—Prompt Corrective Action” above.
Transactions with Affiliates. Any transactions between Old National Bank and its subsidiaries, Old National Bancorp, or any other subsidiary of Old National Bancorp are regulated under federal banking law. The Federal Reserve Act imposes quantitative and qualitative requirements and collateral requirements on covered transactions by Old National Bank with, or for the benefit of, its affiliates, and generally requires those transactions to be on terms at least as favorable to Old National Bank as would be a transaction conducted between unaffiliated third-parties. Covered transactions are defined by statute to include:
• A loan or extension of credit.
• A purchase of securities issued by an affiliate.
• A purchase of assets from an affiliate, unless otherwise exempted by the Federal Reserve.
• Certain derivative transactions that create a credit exposure to an affiliate.
• The acceptance of securities issued by an affiliate as collateral for any loan.
• The issuance of a guarantee, acceptance, or letter of credit on behalf of or for the benefit of an affiliate.
In general, any such transaction by Old National Bank or its subsidiaries must be limited to certain thresholds on an individual and aggregate basis and, credit transactions with, or for the benefit of, an affiliate must be secured by designated amounts of specified collateral.
Federal law also limits Old National Bank’s authority to extend credit to its directors, executive officers, and stockholders who own more than 10% of Common Stock, as well as to entities controlled by such persons. Among other things, any such extension of credit is required to be made on terms that are substantially the same as, and follow credit underwriting procedures that are not less stringent than, those prevailing for comparable transactions with unaffiliated persons. In addition, the terms of such extensions of credit may not involve more than the normal risk of non-repayment or present other unfavorable features and may not exceed certain limitations on the amount of credit extended to such persons individually and in the aggregate.
Community Reinvestment Act . The CRA requires depository institutions to assist in meeting the credit needs of their market areas consistent with safe and sound banking practices. Under the CRA, each depository institution is required to help meet the credit needs of its market areas by, among other things, providing credit to low-income and
12

moderate-income individuals and small businesses in those communities. Federal and state regulators conduct CRA examinations on a regular basis to assess the performance of financial institutions and assign one of four ratings to the institution’s record of meeting the credit needs of its community. Bank regulators take into account CRA ratings when considering approval of a proposed merger or acquisition. Old National Bank received a rating of “satisfactory” in its latest CRA examination.
Deposit Insurance . A large majority of the deposits of Old National Bank are insured up to applicable limits by the Deposit Insurance Fund (“DIF”) which is administered by the FDIC. Insurance of deposits may be terminated by the FDIC upon a finding that the institution engaged or is engaging in unsafe and unsound practices, is in an unsafe or unsound condition to continue operations, or violated any applicable law, regulation, rule, order, or condition imposed by the FDIC or written agreement entered into with the FDIC.
FDIC assessment rates for large institutions that have more than $10 billion of assets, such as Old National Bank, are calculated based on a “scorecard” methodology, based primarily on the difference between the institution’s average of total assets and average tangible equity. The FDIC has the ability to make discretionary adjustments to the total score, up or down, based upon significant risk factors that the FDIC believes are not adequately captured in the scorecard. For large institutions, including Old National Bank, after accounting for potential base-rate adjustments, the total assessment rate could range from 1.5 to 40 basis points on an annualized basis.
In October 2022, the FDIC finalized a rule that increased the initial base deposit insurance assessment rate schedules for all insured depository institutions by 2 basis points, beginning with the first quarterly assessment period of 2023. The increased assessment rate is intended to improve the likelihood that the DIF reserve ratio would reach the required minimum of 1.35 percent by the statutory deadline of September 30, 2028.
On November 16, 2023, the FDIC finalized a rule that imposes special assessments to recover the losses to the DIF resulting from the FDIC’s use, in March 2023, of the systemic risk exception to the least-cost resolution test under the Federal Deposit Insurance Act in connection with the receiverships of Silicon Valley Bank and Signature Bank. The FDIC estimated in approving the rule that those assessed losses total approximately $16.3 billion. The rule provides that this loss estimate will be periodically adjusted, which will affect the amount of the special assessment. As of September 30, 2025, the FDIC’s estimate of the total loss to be recovered through the special assessment was $16.7 billion. Under the rule, the assessment base is the estimated uninsured deposits that an insured depository institution (“IDI”) reported in its December 31, 2022, Call Report, excluding the first $5 billion in estimated uninsured deposits. The special assessments were to be collected at an annual rate of approximately 13.4 basis points per year (3.36 basis points per quarter) over eight quarters in 2024 and 2025, with the first assessment period beginning January 1, 2024. In December 2025, the FDIC reduced the rate at which the assessment is collected for the eighth quarter of the collection period, with an invoice payment date of March 30, 2026, from 3.36 basis points to 2.97 basis points. The special assessments are tax deductible. The total of the special assessments for Old National Bank was estimated at $19.1 million, and such amount was recorded as an expense in the quarter the rule was finalized (the quarter ending December 31, 2023). Old National recorded an additional $3.0 million within FDIC assessment expense for this special assessment in the year ended December 31, 2024. During the year ended December 31, 2025, Old National reduced the previously accrued FDIC special assessment by $3.0 million as the FDIC continues to adjust and refine its estimate of assessed losses.
Depositor Preference . The FDIA provides that, in the event of the “liquidation or other resolution” of an insured depository institution, the claims of depositors of the institution, including the claims of the FDIC as subrogee of insured depositors, and certain claims for administrative expenses of the FDIC as a receiver, will have priority over other general unsecured claims against the institution. If an insured depository institution fails, insured and uninsured depositors, along with the FDIC, will have priority in payment ahead of unsecured, non-deposit creditors, including depositors whose deposits are payable only outside of the United States, and the parent bank holding company with respect to any extensions of credit it may have made to such insured depository institution.
Anti-Tying Restrictions . Generally, a bank is prohibited from extending credit, leasing or selling property, furnishing any service or fixing or varying the consideration for any of the foregoing on the condition that (i) the customer obtains additional credit, property or services from the bank’s parent holding company or any subsidiary of the holding company, or (ii) the customer will not obtain credit, property or services from a competitor of the bank or its affiliates (except to the extent the restriction is a reasonable condition imposed to assure the soundness of the credit extended).
Employee Incentive Compensation . Under regulatory guidance applicable to all banking organizations, incentive compensation policies must be consistent with safety and soundness principles. Under this guidance, financial
13

institutions must review their compensation programs to ensure that they: (i) provide employees with incentives that appropriately balance risk and reward and that do not encourage imprudent risk, (ii) are compatible with effective controls and risk management, and (iii) are supported by strong corporate governance, including active and effective oversight by the banking organization’s board of directors. Monitoring methods and processes used by a banking organization should be commensurate with the size and complexity of the organization and its use of incentive compensation.
During 2016, the federal bank regulatory agencies and the SEC proposed revised rules on incentive-based payment arrangements at specified regulated entities having at least $1 billion of total assets (including the Company and Old National Bank). These proposed rules have not been finalized.
In October 2022, the SEC adopted a final rule directing national securities exchanges and associations, including NASDAQ, to implement listing standards that require all listed companies to adopt policies mandating the recovery or “clawback” of excess incentive-based compensation earned by a current or former executive officer during the three fiscal years preceding a required accounting restatement of financial statements, including to correct an error that would result in a material misstatement if the error were corrected in the current period. The excess compensation would be based on the amount the executive officer would have received had the incentive-based compensation been determined using the restated financial statements. NASDAQ’s listing standards pursuant to the SEC’s rule became effective October 2, 2023. The Company’s clawback policy adopted in accordance with these listing standards is included as Exhibit 97.
Cybersecurity. The federal banking regulators regularly issue new guidance and standards, and update existing guidance and standards, regarding cybersecurity intended to enhance cyber risk management among financial institutions. Financial institutions are expected to comply with such guidance and standards and to accordingly develop appropriate security controls and risk management processes.
State regulators have also been increasingly active in implementing privacy and cybersecurity standards and regulations. Recently, several states have adopted regulations requiring certain financial institutions to implement cybersecurity programs and providing detailed requirements with respect to these programs, including data encryption requirements. Many states have also recently implemented or modified their data breach notification and data privacy requirements. We expect this trend of state-level activity in those areas to continue and are continually monitoring developments in the states in which the Company operates.
In November 2021, the United States federal bank regulatory agencies adopted a rule regarding notification requirements for banking organizations related to significant computer security incidents. Under this rule, a bank holding company, such as Old National Bancorp, and a national bank, such as Old National Bank, are required to notify the Federal Reserve or OCC, respectively, within 36 hours of incidents that have materially disrupted or degraded, or are reasonably likely to materially disrupt or degrade, the banking organization’s ability to deliver services to a material portion of its customer base, jeopardize the viability of key operations of the banking organization, or pose a threat to the financial stability of the United States.
In July 2023, the SEC issued a final rule that requires registrants, including the Company, to (i) report material cybersecurity incidents on Form 8-K within four business days of their being deemed material; (ii) include updated disclosures in Forms 10-K about a registrant’s cybersecurity risk management and strategy, management’s role in assessing and managing material cybersecurity risks, and the board of directors’ oversight of cybersecurity risks; and (iii) present the disclosures in inline XBRL.
Safety and Soundness Standards. In accordance with the FDIA, the federal banking agencies adopted safety and soundness guidelines establishing general standards relating to internal controls, information systems, internal audit systems, loan documentation, credit underwriting, interest rate risk exposure, cybersecurity, liquidity, data protection, asset growth, asset quality, earnings, compensation, fees, and benefits. In general, the guidelines require, among other things, appropriate systems and practices to identify, monitor, and manage the risks and exposures specified in the guidelines. The guidelines prohibit excessive compensation as an unsafe and unsound practice and describe compensation as excessive when the amounts paid are unreasonable or disproportionate to the services performed by an executive officer, employee, director, or principal shareholder. In addition, regulations adopted by the federal banking agencies authorize, but do not require, an agency to order that an institution that has been given notice by an agency that it is not satisfying any of such safety and soundness standards to submit a compliance plan. If, after being so notified, the institution fails to submit an acceptable compliance plan or fails in any material respect to implement an accepted compliance plan, the agency must issue an order directing corrective actions and may issue an order directing other actions of the types to which an undercapitalized institution is subject under the
14