季報
季度報告
10-Q
2026-08-06
老第二銀行提交10-Q季報 披露貸款組合及資本管理策略
AI 繁中摘要
Old Second Bancorp, Inc.(納斯達克:OSBC)已向美國證交會提交截至2026年6月30日的10-Q季度報告,涵蓋2026財年第二季度業績。該公司總部位於伊利諾州奧羅拉,為銀行控股公司,主要透過旗下附屬銀行提供零售及商業銀行服務。
截至2026年8月4日,公司已發行普通股約5,087.6萬股(每股面值1.00美元)。從文件中可見,期內公司資本結構維持穩定,保留了留存收益,並設有庫存股安排,反映其持續回購股票的資本管理策略。
在資產負債及貸款組合方面,公司對貸款分類作出詳細披露,涵蓋商業地產(自用及投資)、住宅按揭、建築貸款、設備融資租賃、住宅權益貸款及其他消費貸款組合。信用風險分類包括「正常」、「特別關注」、「次級」及「可疑」等類別,顯示管理層對資產質素保持審慎監察。期內亦有貸款修訂安排,包括延長到期日、降息、還款修改及本金削減等紓困措施。
公司披露了多項金融工具,包括利率掉期、遠期合約等衍生工具,用於对冲利率風險。此外,文件亦載有按公允價值計量的證券投資組合,涵蓋美國國債、政府機構證券、市政債券、按揭抵押證券
展開英文正文
OLD SECOND BANCORP INC_June 30, 2026 0000357173OLD SECOND BANCORP INC--12-312026Q2falsehttp://www.oldsecond.com/20260630#ThreeMonthsSecuredOvernightFinancingRateMemberhttp://www.oldsecond.com/20260630#ThreeMonthsSecuredOvernightFinancingRateMember0000357173us-gaap:TreasuryStockCommonMember2026-06-300000357173us-gaap:RetainedEarningsMember2026-06-300000357173us-gaap:AdditionalPaidInCapitalMember2026-06-300000357173us-gaap:AccumulatedOtherComprehensiveIncomeMember2026-06-300000357173us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2026-06-300000357173us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2026-06-300000357173us-gaap:TreasuryStockCommonMember2026-03-310000357173us-gaap:RetainedEarningsMember2026-03-310000357173us-gaap:AdditionalPaidInCapitalMember2026-03-310000357173us-gaap:AccumulatedOtherComprehensiveIncomeMember2026-03-310000357173us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2026-03-310000357173us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2026-03-310000357173us-gaap:TreasuryStockCommonMember2025-12-310000357173us-gaap:RetainedEarningsMember2025-12-310000357173us-gaap:AdditionalPaidInCapitalMember2025-12-310000357173us-gaap:AccumulatedOtherComprehensiveIncomeMember2025-12-310000357173us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2025-12-310000357173us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2025-12-310000357173us-gaap:TreasuryStockCommonMember2025-06-300000357173us-gaap:RetainedEarningsMember2025-06-300000357173us-gaap:AdditionalPaidInCapitalMember2025-06-300000357173us-gaap:AccumulatedOtherComprehensiveIncomeMember2025-06-300000357173us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2025-06-300000357173us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2025-06-300000357173us-gaap:TreasuryStockCommonMember2025-03-310000357173us-gaap:RetainedEarningsMember2025-03-310000357173us-gaap:AdditionalPaidInCapitalMember2025-03-310000357173us-gaap:AccumulatedOtherComprehensiveIncomeMember2025-03-310000357173us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2025-03-310000357173us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2025-03-310000357173us-gaap:TreasuryStockCommonMember2024-12-310000357173us-gaap:RetainedEarningsMember2024-12-310000357173us-gaap:AdditionalPaidInCapitalMember2024-12-310000357173us-gaap:AccumulatedOtherComprehensiveIncomeMember2024-12-310000357173us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2024-12-310000357173us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2024-12-310000357173us-gaap:CommonStockMember2026-04-012026-06-300000357173us-gaap:CommonStockMember2026-01-012026-06-300000357173us-gaap:CommonStockMember2025-04-012025-06-300000357173us-gaap:CommonStockMember2025-01-012025-06-300000357173osbc:EquityIncentivePlan2019Member2026-06-300000357173osbc:EquityIncentivePlan2019Member2025-05-310000357173osbc:EquityIncentivePlan2019Member2021-05-310000357173osbc:EquityIncentivePlan2019Member2019-05-310000357173osbc:EquityIncentivePlan2019Member2025-05-012025-05-310000357173osbc:EquityIncentivePlan2019Member2021-05-012021-05-310000357173osbc:RestrictedStockAndRestrictedStockUnitsMember2025-12-310000357173osbc:RestrictedStockAndRestrictedStockUnitsMemberosbc:EquityIncentivePlan2019Member2026-01-012026-06-300000357173srt:WeightedAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageServicingRightsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:WeightedAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageServicingRightsMemberus-gaap:MeasurementInputConstantPrepaymentRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:MinimumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageServicingRightsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:MinimumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageServicingRightsMemberus-gaap:MeasurementInputConstantPrepaymentRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageServicingRightsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageServicingRightsMemberus-gaap:MeasurementInputConstantPrepaymentRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:WeightedAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageServicingRightsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173srt:WeightedAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageServicingRightsMemberus-gaap:MeasurementInputConstantPrepaymentRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173srt:MinimumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageServicingRightsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173srt:MinimumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageServicingRightsMemberus-gaap:MeasurementInputConstantPrepaymentRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173srt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageServicingRightsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173srt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageServicingRightsMemberus-gaap:MeasurementInputConstantPrepaymentRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageServicingRightsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageServicingRightsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173srt:MaximumMember2026-06-300000357173srt:MaximumMember2025-06-300000357173us-gaap:MortgageBankingMember2026-04-012026-06-300000357173us-gaap:FiduciaryAndTrustMember2026-04-012026-06-300000357173us-gaap:DepositAccountMember2026-04-012026-06-300000357173osbc:MortgageServicingMember2026-04-012026-06-300000357173us-gaap:MortgageBankingMember2026-01-012026-06-300000357173us-gaap:FiduciaryAndTrustMember2026-01-012026-06-300000357173us-gaap:DepositAccountMember2026-01-012026-06-300000357173osbc:MortgageServicingMember2026-01-012026-06-300000357173us-gaap:MortgageBankingMember2025-04-012025-06-300000357173us-gaap:FiduciaryAndTrustMember2025-04-012025-06-300000357173us-gaap:DepositAccountMember2025-04-012025-06-300000357173osbc:MortgageServicingMember2025-04-012025-06-300000357173us-gaap:MortgageBankingMember2025-01-012025-06-300000357173us-gaap:FiduciaryAndTrustMember2025-01-012025-06-300000357173us-gaap:DepositAccountMember2025-01-012025-06-300000357173osbc:MortgageServicingMember2025-01-012025-06-300000357173osbc:OldSecondCapitalTrustIIMember2007-04-012007-04-300000357173us-gaap:AccumulatedOtherComprehensiveIncomeMember2026-04-012026-06-300000357173us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2026-04-012026-06-300000357173us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2026-04-012026-06-300000357173us-gaap:AccumulatedOtherComprehensiveIncomeMember2026-01-012026-06-300000357173us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2026-01-012026-06-300000357173us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2026-01-012026-06-300000357173us-gaap:AccumulatedOtherComprehensiveIncomeMember2025-04-012025-06-300000357173us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2025-04-012025-06-300000357173us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2025-04-012025-06-300000357173us-gaap:AccumulatedOtherComprehensiveIncomeMember2025-01-012025-06-300000357173us-gaap:AccumulatedNetUnrealizedInvestmentGainLossMember2025-01-012025-06-300000357173us-gaap:AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember2025-01-012025-06-300000357173us-gaap:OtherLiabilitiesMemberus-gaap:UnfundedLoanCommitmentMember2026-06-300000357173us-gaap:ResidentialPortfolioSegmentMember2026-06-300000357173us-gaap:ResidentialPortfolioSegmentMember2025-12-310000357173osbc:CommitmentsToExtendCreditToBorrowersMemberus-gaap:PerformanceGuaranteeMemberosbc:VariableMember2026-06-300000357173osbc:CommitmentsToExtendCreditToBorrowersMemberus-gaap:PerformanceGuaranteeMemberosbc:FixedMember2026-06-300000357173osbc:CommitmentsToExtendCreditToBorrowersMemberus-gaap:FinancialStandbyLetterOfCreditMemberosbc:VariableMember2026-06-300000357173osbc:CommitmentsToExtendCreditToBorrowersMemberus-gaap:FinancialStandbyLetterOfCreditMemberosbc:FixedMember2026-06-300000357173osbc:CommitmentsToExtendCreditToBorrowersMemberus-gaap:PerformanceGuaranteeMember2026-06-300000357173osbc:CommitmentsToExtendCreditToBorrowersMemberus-gaap:FinancialStandbyLetterOfCreditMember2026-06-300000357173osbc:CommitmentsToExtendCreditToBorrowersMemberosbc:VariableMember2026-06-300000357173osbc:CommitmentsToExtendCreditToBorrowersMemberosbc:FixedMember2026-06-300000357173osbc:VariableMember2026-06-300000357173osbc:FixedMember2026-06-300000357173osbc:CommitmentsToExtendCreditToBorrowersMember2026-06-300000357173osbc:CommitmentsToExtendCreditToBorrowersMemberus-gaap:PerformanceGuaranteeMemberosbc:VariableMember2025-12-310000357173osbc:CommitmentsToExtendCreditToBorrowersMemberus-gaap:PerformanceGuaranteeMemberosbc:FixedMember2025-12-310000357173osbc:CommitmentsToExtendCreditToBorrowersMemberus-gaap:FinancialStandbyLetterOfCreditMemberosbc:VariableMember2025-12-310000357173osbc:CommitmentsToExtendCreditToBorrowersMemberus-gaap:FinancialStandbyLetterOfCreditMemberosbc:FixedMember2025-12-310000357173osbc:CommitmentsToExtendCreditToBorrowersMemberus-gaap:PerformanceGuaranteeMember2025-12-310000357173osbc:CommitmentsToExtendCreditToBorrowersMemberus-gaap:FinancialStandbyLetterOfCreditMember2025-12-310000357173osbc:CommitmentsToExtendCreditToBorrowersMemberosbc:VariableMember2025-12-310000357173osbc:CommitmentsToExtendCreditToBorrowersMemberosbc:FixedMember2025-12-310000357173osbc:VariableMember2025-12-310000357173osbc:FixedMember2025-12-310000357173osbc:CommitmentsToExtendCreditToBorrowersMember2025-12-310000357173osbc:OldSecondCapitalTrustIIMemberus-gaap:JuniorSubordinatedDebtMember2026-06-300000357173osbc:RestrictedStockAndRestrictedStockUnitsMember2025-01-012025-06-300000357173us-gaap:UnallocatedFinancingReceivablesMemberosbc:ExtendedMaturityInterestRateReductionPaymentModificationAndPrincipalReductionMember2026-04-012026-06-300000357173us-gaap:ConstructionMemberus-gaap:ExtendedMaturityMember2026-04-012026-06-300000357173us-gaap:CommercialPortfolioSegmentMemberus-gaap:ExtendedMaturityMember2026-04-012026-06-300000357173us-gaap:CommercialPortfolioSegmentMemberosbc:ExtendedMaturityAndPaymentModificationMember2026-04-012026-06-300000357173osbc:PowersportPortfolioSegmentMemberosbc:InterestRateReductionAndPaymentModificationMember2026-04-012026-06-300000357173osbc:PowersportPortfolioSegmentMemberosbc:ExtendedMaturityInterestRateReductionPaymentModificationAndPrincipalReductionMember2026-04-012026-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:ExtendedMaturityMember2026-04-012026-06-300000357173osbc:CommercialRealEstateInvestorMemberus-gaap:ExtendedMaturityAndInterestRateReductionMember2026-04-012026-06-300000357173us-gaap:ExtendedMaturityMember2026-04-012026-06-300000357173us-gaap:ExtendedMaturityAndInterestRateReductionMember2026-04-012026-06-300000357173osbc:InterestRateReductionAndPaymentModificationMember2026-04-012026-06-300000357173osbc:ExtendedMaturityInterestRateReductionPaymentModificationAndPrincipalReductionMember2026-04-012026-06-300000357173osbc:ExtendedMaturityAndPaymentModificationMember2026-04-012026-06-300000357173us-gaap:UnallocatedFinancingReceivablesMemberosbc:ExtendedMaturityInterestRateReductionPaymentModificationAndPrincipalReductionMember2026-01-012026-06-300000357173us-gaap:HomeEquityMemberus-gaap:ExtendedMaturityMember2026-01-012026-06-300000357173us-gaap:ConstructionMemberus-gaap:ExtendedMaturityMember2026-01-012026-06-300000357173us-gaap:CommercialPortfolioSegmentMemberus-gaap:ExtendedMaturityMember2026-01-012026-06-300000357173us-gaap:CommercialPortfolioSegmentMemberosbc:ExtendedMaturityAndPaymentModificationMember2026-01-012026-06-300000357173osbc:PowersportPortfolioSegmentMemberosbc:InterestRateReductionAndPaymentModificationMember2026-01-012026-06-300000357173osbc:PowersportPortfolioSegmentMemberosbc:ExtendedMaturityInterestRateReductionPaymentModificationAndPrincipalReductionMember2026-01-012026-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:ExtendedMaturityMember2026-01-012026-06-300000357173osbc:CommercialRealEstateInvestorMemberus-gaap:ExtendedMaturityAndInterestRateReductionMember2026-01-012026-06-300000357173us-gaap:ExtendedMaturityMember2026-01-012026-06-300000357173us-gaap:ExtendedMaturityAndInterestRateReductionMember2026-01-012026-06-300000357173osbc:InterestRateReductionAndPaymentModificationMember2026-01-012026-06-300000357173osbc:ExtendedMaturityInterestRateReductionPaymentModificationAndPrincipalReductionMember2026-01-012026-06-300000357173osbc:ExtendedMaturityAndPaymentModificationMember2026-01-012026-06-300000357173us-gaap:UnallocatedFinancingReceivablesMemberus-gaap:FinancingReceivables60To89DaysPastDueMember2025-07-012026-06-300000357173us-gaap:UnallocatedFinancingReceivablesMemberus-gaap:FinancialAssetPastDueMember2025-07-012026-06-300000357173us-gaap:UnallocatedFinancingReceivablesMemberus-gaap:FinancialAssetNotPastDueMember2025-07-012026-06-300000357173us-gaap:HomeEquityMemberus-gaap:FinancialAssetNotPastDueMember2025-07-012026-06-300000357173us-gaap:ConstructionMemberus-gaap:FinancialAssetNotPastDueMember2025-07-012026-06-300000357173us-gaap:CommercialPortfolioSegmentMemberus-gaap:FinancialAssetNotPastDueMember2025-07-012026-06-300000357173osbc:PowersportPortfolioSegmentMemberus-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember2025-07-012026-06-300000357173osbc:PowersportPortfolioSegmentMemberus-gaap:FinancingReceivables60To89DaysPastDueMember2025-07-012026-06-300000357173osbc:PowersportPortfolioSegmentMemberus-gaap:FinancingReceivables30To59DaysPastDueMember2025-07-012026-06-300000357173osbc:PowersportPortfolioSegmentMemberus-gaap:FinancialAssetPastDueMember2025-07-012026-06-300000357173osbc:PowersportPortfolioSegmentMemberus-gaap:FinancialAssetNotPastDueMember2025-07-012026-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember2025-07-012026-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:FinancialAssetPastDueMember2025-07-012026-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:FinancialAssetNotPastDueMember2025-07-012026-06-300000357173osbc:CommercialRealEstateInvestorMemberus-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember2025-07-012026-06-300000357173osbc:CommercialRealEstateInvestorMemberus-gaap:FinancialAssetPastDueMember2025-07-012026-06-300000357173osbc:CommercialRealEstateInvestorMemberus-gaap:FinancialAssetNotPastDueMember2025-07-012026-06-300000357173us-gaap:UnallocatedFinancingReceivablesMember2025-07-012026-06-300000357173us-gaap:HomeEquityMember2025-07-012026-06-300000357173us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember2025-07-012026-06-300000357173us-gaap:FinancingReceivables60To89DaysPastDueMember2025-07-012026-06-300000357173us-gaap:FinancingReceivables30To59DaysPastDueMember2025-07-012026-06-300000357173us-gaap:FinancialAssetPastDueMember2025-07-012026-06-300000357173us-gaap:FinancialAssetNotPastDueMember2025-07-012026-06-300000357173us-gaap:ConstructionMember2025-07-012026-06-300000357173us-gaap:CommercialPortfolioSegmentMember2025-07-012026-06-300000357173osbc:PowersportPortfolioSegmentMember2025-07-012026-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMember2025-07-012026-06-300000357173osbc:CommercialRealEstateInvestorMember2025-07-012026-06-3000003571732025-07-012026-06-300000357173us-gaap:CommercialPortfolioSegmentMemberus-gaap:ExtendedMaturityMember2025-04-012025-06-300000357173us-gaap:CommercialPortfolioSegmentMemberosbc:ExtendedMaturityAndPaymentModificationMember2025-04-012025-06-300000357173osbc:MultiFamilyLoanMemberus-gaap:ExtendedMaturityMember2025-04-012025-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:ExtendedMaturityMember2025-04-012025-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:ExtendedMaturityAndInterestRateReductionMember2025-04-012025-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberosbc:ExtendedMaturityAndPaymentModificationMember2025-04-012025-06-300000357173us-gaap:ExtendedMaturityMember2025-04-012025-06-300000357173us-gaap:ExtendedMaturityAndInterestRateReductionMember2025-04-012025-06-300000357173osbc:ExtendedMaturityAndPaymentModificationMember2025-04-012025-06-300000357173us-gaap:CommercialPortfolioSegmentMemberus-gaap:ExtendedMaturityMember2025-01-012025-06-300000357173us-gaap:CommercialPortfolioSegmentMemberosbc:ExtendedMaturityAndPaymentModificationMember2025-01-012025-06-300000357173osbc:MultiFamilyLoanMemberus-gaap:ExtendedMaturityMember2025-01-012025-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:ExtendedMaturityMember2025-01-012025-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:ExtendedMaturityAndInterestRateReductionMember2025-01-012025-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberosbc:ExtendedMaturityAndPaymentModificationMember2025-01-012025-06-300000357173osbc:CommercialRealEstateInvestorMemberus-gaap:ExtendedMaturityAndInterestRateReductionMember2025-01-012025-06-300000357173osbc:CommercialRealEstateInvestorMemberosbc:ExtendedMaturityAndPaymentModificationMember2025-01-012025-06-300000357173us-gaap:ExtendedMaturityMember2025-01-012025-06-300000357173us-gaap:ExtendedMaturityAndInterestRateReductionMember2025-01-012025-06-300000357173osbc:ExtendedMaturityAndPaymentModificationMember2025-01-012025-06-300000357173us-gaap:CommercialPortfolioSegmentMemberus-gaap:FinancingReceivables30To59DaysPastDueMember2024-07-012025-06-300000357173us-gaap:CommercialPortfolioSegmentMemberus-gaap:FinancialAssetPastDueMember2024-07-012025-06-300000357173us-gaap:CommercialPortfolioSegmentMemberus-gaap:FinancialAssetNotPastDueMember2024-07-012025-06-300000357173osbc:MultiFamilyLoanMemberus-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember2024-07-012025-06-300000357173osbc:MultiFamilyLoanMemberus-gaap:FinancialAssetPastDueMember2024-07-012025-06-300000357173osbc:MultiFamilyLoanMemberus-gaap:FinancialAssetNotPastDueMember2024-07-012025-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember2024-07-012025-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:FinancingReceivables60To89DaysPastDueMember2024-07-012025-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:FinancingReceivables30To59DaysPastDueMember2024-07-012025-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:FinancialAssetPastDueMember2024-07-012025-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:FinancialAssetNotPastDueMember2024-07-012025-06-300000357173osbc:CommercialRealEstateInvestorMemberus-gaap:FinancialAssetNotPastDueMember2024-07-012025-06-300000357173us-gaap:FinancingReceivablesEqualToGreaterThan90DaysPastDueMember2024-07-012025-06-300000357173us-gaap:FinancingReceivables60To89DaysPastDueMember2024-07-012025-06-300000357173us-gaap:FinancingReceivables30To59DaysPastDueMember2024-07-012025-06-300000357173us-gaap:FinancialAssetPastDueMember2024-07-012025-06-300000357173us-gaap:FinancialAssetNotPastDueMember2024-07-012025-06-300000357173us-gaap:CommercialPortfolioSegmentMember2024-07-012025-06-300000357173osbc:MultiFamilyLoanMember2024-07-012025-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMember2024-07-012025-06-300000357173osbc:CommercialRealEstateInvestorMember2024-07-012025-06-3000003571732024-07-012025-06-300000357173us-gaap:FederalHomeLoanBankAdvancesMember2025-12-310000357173osbc:MortgageServicingRightsMember2026-06-300000357173osbc:MortgageServicingRightsMember2025-12-310000357173us-gaap:USStatesAndPoliticalSubdivisionsMember2025-06-300000357173us-gaap:AssetBackedSecuritiesMember2025-06-300000357173osbc:MortgageServicingRightsMember2025-06-300000357173us-gaap:USStatesAndPoliticalSubdivisionsMember2024-12-310000357173us-gaap:AssetBackedSecuritiesMember2024-12-310000357173osbc:MortgageServicingRightsMember2024-12-310000357173us-gaap:USStatesAndPoliticalSubdivisionsMember2026-01-012026-06-300000357173us-gaap:USStatesAndPoliticalSubdivisionsMember2025-01-012025-06-300000357173us-gaap:AssetBackedSecuritiesMember2025-01-012025-06-300000357173osbc:MortgageServicingRightsMember2026-01-012026-06-300000357173osbc:MortgageServicingRightsMember2025-01-012025-06-300000357173us-gaap:UnusedLinesOfCreditMemberosbc:VariableMember2026-06-300000357173us-gaap:UnusedLinesOfCreditMemberosbc:FixedMember2026-06-300000357173us-gaap:UnusedLinesOfCreditMember2026-06-300000357173us-gaap:UnusedLinesOfCreditMemberosbc:VariableMember2025-12-310000357173us-gaap:UnusedLinesOfCreditMemberosbc:FixedMember2025-12-310000357173us-gaap:UnusedLinesOfCreditMember2025-12-310000357173osbc:RestrictedStockAndRestrictedStockUnitsMember2026-06-300000357173osbc:RestrictedStockAndRestrictedStockUnitsMember2026-01-012026-06-300000357173osbc:O2026Q3DividendsMemberus-gaap:SubsequentEventMember2026-07-210000357173us-gaap:RetainedEarningsMember2026-04-012026-06-300000357173us-gaap:RetainedEarningsMember2026-01-012026-06-300000357173us-gaap:RetainedEarningsMember2025-04-012025-06-300000357173us-gaap:RetainedEarningsMember2025-01-012025-06-300000357173osbc:O2026Q3DividendsMemberus-gaap:SubsequentEventMember2026-07-012026-07-210000357173us-gaap:InterestRateSwapMemberosbc:CashFlowHedgesOfCertainVariableRateCommercialAndCommercialRealEstateLoanPoolsMemberus-gaap:DesignatedAsHedgingInstrumentMember2026-06-300000357173us-gaap:InterestRateContractMemberosbc:CashFlowHedgeOfJuniorSubordinatedDebenturesAndWasExecutedToPayFixedAndReceiveVariableRateCashFlowsMemberus-gaap:DesignatedAsHedgingInstrumentMember2026-06-300000357173us-gaap:InterestRateSwapMemberus-gaap:NondesignatedMember2026-06-300000357173osbc:DerivativeCommitmentsMemberus-gaap:NondesignatedMember2026-06-300000357173us-gaap:InterestRateSwapMemberosbc:CashFlowHedgesOfCertainVariableRateCommercialAndCommercialRealEstateLoanPoolsMemberus-gaap:DesignatedAsHedgingInstrumentMember2025-12-310000357173us-gaap:InterestRateContractMemberosbc:CashFlowHedgeOfJuniorSubordinatedDebenturesAndWasExecutedToPayFixedAndReceiveVariableRateCashFlowsMemberus-gaap:DesignatedAsHedgingInstrumentMember2025-12-310000357173us-gaap:InterestRateSwapMemberus-gaap:NondesignatedMember2025-12-310000357173osbc:DerivativeCommitmentsMemberus-gaap:NondesignatedMember2025-12-310000357173us-gaap:InterestRateSwapMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2026-06-300000357173us-gaap:ForwardContractsMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2026-06-300000357173us-gaap:InterestRateSwapMemberus-gaap:FairValueMeasurementsRecurringMember2026-06-300000357173us-gaap:ForwardContractsMemberus-gaap:FairValueMeasurementsRecurringMember2026-06-300000357173us-gaap:InterestRateSwapMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2025-12-310000357173us-gaap:InterestRateSwapMemberus-gaap:FairValueMeasurementsRecurringMember2025-12-310000357173us-gaap:InterestRateContractMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2026-06-300000357173us-gaap:InterestRateContractMemberus-gaap:FairValueMeasurementsRecurringMember2026-06-300000357173us-gaap:InterestRateContractMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2025-12-310000357173us-gaap:ForwardContractsMemberus-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2025-12-310000357173us-gaap:InterestRateContractMemberus-gaap:FairValueMeasurementsRecurringMember2025-12-310000357173us-gaap:ForwardContractsMemberus-gaap:FairValueMeasurementsRecurringMember2025-12-310000357173us-gaap:JuniorSubordinatedDebtMember2026-06-300000357173us-gaap:JuniorSubordinatedDebtMember2025-12-310000357173srt:WeightedAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:WeightedAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberosbc:MeasurementInputLiquidityPremiumMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:WeightedAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:MinimumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:MinimumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberosbc:MeasurementInputLiquidityPremiumMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:MinimumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberosbc:MeasurementInputLiquidityPremiumMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173srt:WeightedAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173srt:WeightedAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberosbc:MeasurementInputLiquidityPremiumMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173srt:WeightedAverageMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173srt:MinimumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173srt:MinimumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberosbc:MeasurementInputLiquidityPremiumMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173srt:MinimumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173srt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173srt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberosbc:MeasurementInputLiquidityPremiumMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173srt:MaximumMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2026-06-300000357173us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMember2026-06-300000357173us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMember2026-06-300000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMember2026-06-300000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USGovernmentCorporationsAndAgenciesSecuritiesMember2026-06-300000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquitySecuritiesMember2026-06-300000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CollateralizedMortgageObligationsMember2026-06-300000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CollateralizedLoanObligationsMember2026-06-300000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMember2026-06-300000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageBackedSecuritiesIssuedByUSGovernmentAgenciesMember2026-06-300000357173us-gaap:FairValueInputsLevel1Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasurySecuritiesMember2026-06-300000357173us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasurySecuritiesMember2026-06-300000357173us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMember2026-06-300000357173us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USGovernmentCorporationsAndAgenciesSecuritiesMember2026-06-300000357173us-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquitySecuritiesMember2026-06-300000357173us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CollateralizedMortgageObligationsMember2026-06-300000357173us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CollateralizedLoanObligationsMember2026-06-300000357173us-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMember2026-06-300000357173us-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageBackedSecuritiesIssuedByUSGovernmentAgenciesMember2026-06-300000357173us-gaap:FairValueInputsLevel3Member2026-06-300000357173us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMemberus-gaap:MeasurementInputDiscountRateMemberosbc:DiscountedCashFlowValuationTechniqueMember2025-12-310000357173us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMember2025-12-310000357173us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMember2025-12-310000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMember2025-12-310000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USGovernmentCorporationsAndAgenciesSecuritiesMember2025-12-310000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquitySecuritiesMember2025-12-310000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CollateralizedMortgageObligationsMember2025-12-310000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:CollateralizedLoanObligationsMember2025-12-310000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMember2025-12-310000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageBackedSecuritiesIssuedByUSGovernmentAgenciesMember2025-12-310000357173us-gaap:FairValueInputsLevel1Memberus-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasurySecuritiesMember2025-12-310000357173us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USTreasurySecuritiesMember2025-12-310000357173us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USStatesAndPoliticalSubdivisionsMember2025-12-310000357173us-gaap:FairValueMeasurementsRecurringMemberus-gaap:USGovernmentCorporationsAndAgenciesSecuritiesMember2025-12-310000357173us-gaap:FairValueMeasurementsRecurringMemberus-gaap:EquitySecuritiesMember2025-12-310000357173us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CollateralizedMortgageObligationsMember2025-12-310000357173us-gaap:FairValueMeasurementsRecurringMemberus-gaap:CollateralizedLoanObligationsMember2025-12-310000357173us-gaap:FairValueMeasurementsRecurringMemberus-gaap:AssetBackedSecuritiesMember2025-12-310000357173us-gaap:FairValueMeasurementsRecurringMemberosbc:MortgageBackedSecuritiesIssuedByUSGovernmentAgenciesMember2025-12-310000357173us-gaap:FairValueInputsLevel3Member2025-12-310000357173us-gaap:AssetPledgedAsCollateralWithRightMemberus-gaap:SecuritiesSoldUnderAgreementsToRepurchaseMember2026-06-300000357173us-gaap:AssetPledgedAsCollateralWithRightMemberus-gaap:SecuritiesSoldUnderAgreementsToRepurchaseMember2025-12-310000357173us-gaap:InterestRateSwapMember2025-06-300000357173us-gaap:SubordinatedDebtMember2026-06-300000357173us-gaap:NotesPayableToBanksMember2026-06-300000357173us-gaap:JuniorSubordinatedDebtMember2026-06-300000357173osbc:OtherShortTermBorrowingsMember2026-06-300000357173us-gaap:SubordinatedDebtMember2025-12-310000357173us-gaap:SecuritiesSoldUnderAgreementsToRepurchaseMember2025-12-310000357173us-gaap:NotesPayableToBanksMember2025-12-310000357173us-gaap:JuniorSubordinatedDebtMember2025-12-310000357173osbc:OtherShortTermBorrowingsMember2025-12-310000357173osbc:OldSecondCapitalTrustIIMemberus-gaap:DebtInstrumentRedemptionPeriodOneMember2026-06-300000357173osbc:SubordinatedNotesDue2031Member2026-06-300000357173osbc:OldSecondCapitalTrustIIMemberus-gaap:DebtInstrumentRedemptionPeriodOneMember2025-06-300000357173osbc:SubordinatedNotesDue2031Member2026-04-150000357173osbc:SubordinatedNotesDue2031Member2021-06-300000357173osbc:SubordinatedNotesDue2031Member2026-04-152026-04-150000357173osbc:SubordinatedNotesDue2031Member2021-04-012021-06-300000357173us-gaap:CommonStockMember2026-06-300000357173us-gaap:CommonStockMember2026-03-310000357173us-gaap:CommonStockMember2025-12-310000357173us-gaap:CommonStockMember2025-06-300000357173us-gaap:CommonStockMember2025-03-310000357173us-gaap:CommonStockMember2024-12-310000357173osbc:InterestRateLockCommitmentsAndForwardContractsMemberus-gaap:NondesignatedMember2026-06-300000357173osbc:OsbcAffiliatesMemberus-gaap:InterestRateContractMemberus-gaap:DesignatedAsHedgingInstrumentMember2026-06-300000357173osbc:CommercialLoanCustomersMemberus-gaap:InterestRateContractMemberus-gaap:NondesignatedMember2026-06-300000357173us-gaap:OtherContractMemberus-gaap:NondesignatedMember2026-06-300000357173us-gaap:NondesignatedMember2026-06-300000357173us-gaap:DesignatedAsHedgingInstrumentMember2026-06-300000357173osbc:OsbcAffiliatesMemberus-gaap:InterestRateContractMemberus-gaap:DesignatedAsHedgingInstrumentMember2025-12-310000357173osbc:CommercialLoanCustomersMemberus-gaap:InterestRateContractMemberus-gaap:NondesignatedMember2025-12-310000357173us-gaap:OtherContractMemberus-gaap:NondesignatedMember2025-12-310000357173osbc:InterestRateLockCommitmentsAndForwardContractsMemberus-gaap:NondesignatedMember2025-12-310000357173us-gaap:NondesignatedMember2025-12-310000357173us-gaap:DesignatedAsHedgingInstrumentMember2025-12-310000357173us-gaap:InterestRateSwapMember2026-06-300000357173osbc:TwoFinancialInstitutionsMember2026-06-300000357173us-gaap:InterestRateSwapMember2025-12-310000357173osbc:TwoFinancialInstitutionsMember2025-12-310000357173us-gaap:FairValueInputsLevel1Member2026-06-300000357173us-gaap:FairValueInputsLevel1Member2025-12-310000357173osbc:BancorpFinancialMember2025-07-012025-07-010000357173osbc:MortgageBackedAndCollateralizedMortgageObligationsMember2026-06-300000357173us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember2026-06-300000357173us-gaap:MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember2025-12-310000357173us-gaap:EquitySecuritiesMember2026-06-300000357173us-gaap:USTreasurySecuritiesMember2025-12-310000357173us-gaap:EquitySecuritiesMember2025-12-310000357173osbc:OtherRealEstateOwnedMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsNonrecurringMember2026-06-300000357173osbc:ImpairedLoansMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsNonrecurringMember2026-06-300000357173osbc:ImpairedLoansMemberus-gaap:CarryingReportedAmountFairValueDisclosureMemberus-gaap:FairValueMeasurementsNonrecurringMember2026-06-300000357173us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2026-06-300000357173us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsNonrecurringMember2026-06-300000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2026-06-300000357173us-gaap:FairValueInputsLevel1Memberus-gaap:FairValueMeasurementsRecurringMember2026-06-300000357173us-gaap:FairValueMeasurementsRecurringMember2026-06-300000357173us-gaap:FairValueMeasurementsNonrecurringMember2026-06-300000357173osbc:OtherRealEstateOwnedMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsNonrecurringMember2025-12-310000357173osbc:ImpairedLoansMemberus-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsNonrecurringMember2025-12-310000357173osbc:ImpairedLoansMemberus-gaap:CarryingReportedAmountFairValueDisclosureMemberus-gaap:FairValueMeasurementsNonrecurringMember2025-12-310000357173us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsRecurringMember2025-12-310000357173us-gaap:FairValueInputsLevel3Memberus-gaap:FairValueMeasurementsNonrecurringMember2025-12-310000357173us-gaap:FairValueInputsLevel2Memberus-gaap:FairValueMeasurementsRecurringMember2025-12-310000357173us-gaap:FairValueInputsLevel1Memberus-gaap:FairValueMeasurementsRecurringMember2025-12-310000357173us-gaap:FairValueMeasurementsRecurringMember2025-12-310000357173us-gaap:FairValueMeasurementsNonrecurringMember2025-12-310000357173us-gaap:AdditionalPaidInCapitalMember2026-04-012026-06-300000357173us-gaap:AdditionalPaidInCapitalMember2026-01-012026-06-300000357173us-gaap:AdditionalPaidInCapitalMember2025-04-012025-06-300000357173us-gaap:AdditionalPaidInCapitalMember2025-01-012025-06-300000357173us-gaap:TreasuryStockCommonMember2026-04-012026-06-300000357173us-gaap:TreasuryStockCommonMember2026-01-012026-06-300000357173us-gaap:TreasuryStockCommonMember2025-04-012025-06-300000357173us-gaap:TreasuryStockCommonMember2025-01-012025-06-300000357173osbc:OldSecondCapitalTrustIIMember2017-01-012017-06-150000357173osbc:OldSecondCapitalTrustIIMember2026-01-012026-06-300000357173srt:SubsidiariesMember2026-06-300000357173srt:SubsidiariesMember2025-12-310000357173osbc:RestrictedStockAndRestrictedStockUnitsMember2026-04-012026-06-300000357173osbc:RestrictedStockAndRestrictedStockUnitsMember2025-04-012025-06-300000357173osbc:OtherRealEstateOwnedMemberus-gaap:FairValueMeasurementsNonrecurringMember2025-12-310000357173us-gaap:InterestRateSwapMember2026-01-012026-06-300000357173osbc:TwoFinancialInstitutionsMember2026-01-012026-06-300000357173us-gaap:InterestRateSwapMember2025-01-012025-12-310000357173osbc:TwoFinancialInstitutionsMember2025-01-012025-12-310000357173us-gaap:SecuritiesSoldUnderAgreementsToRepurchaseMember2026-06-300000357173us-gaap:AccountsReceivableMemberus-gaap:CustomerConcentrationRiskMemberosbc:RealEstatePortfolioSegmentMember2026-01-012026-06-300000357173us-gaap:AccountsReceivableMemberus-gaap:CustomerConcentrationRiskMemberosbc:RealEstatePortfolioSegmentMember2025-01-012025-12-310000357173us-gaap:FairValueInputsLevel2Member2026-06-300000357173us-gaap:EstimateOfFairValueFairValueDisclosureMember2026-06-300000357173us-gaap:CarryingReportedAmountFairValueDisclosureMember2026-06-300000357173us-gaap:FairValueInputsLevel2Member2025-12-310000357173us-gaap:EstimateOfFairValueFairValueDisclosureMember2025-12-310000357173us-gaap:CarryingReportedAmountFairValueDisclosureMember2025-12-310000357173srt:SubsidiariesMember2026-01-012026-06-3000003571732025-01-012025-12-310000357173osbc:OtherRealEstateOwnedMemberus-gaap:FairValueMeasurementsNonrecurringMember2026-06-300000357173osbc:ImpairedLoansMemberus-gaap:FairValueMeasurementsNonrecurringMember2026-01-012026-06-300000357173osbc:ImpairedLoansMemberus-gaap:FairValueMeasurementsNonrecurringMember2025-01-012025-12-310000357173osbc:ImpairedLoansMemberus-gaap:FairValueMeasurementsNonrecurringMember2026-06-300000357173osbc:ImpairedLoansMemberus-gaap:FairValueMeasurementsNonrecurringMember2025-12-310000357173us-gaap:ConstructionMember2026-04-012026-06-300000357173osbc:MultiFamilyLoanMember2026-04-012026-06-300000357173us-gaap:ConstructionMember2026-01-012026-06-300000357173osbc:MultiFamilyLoanMember2026-01-012026-06-300000357173osbc:MultiFamilyLoanMember2025-04-012025-06-300000357173osbc:MultiFamilyLoanMember2025-01-012025-06-300000357173us-gaap:PerformingFinancingReceivableMemberus-gaap:UnallocatedFinancingReceivablesMemberosbc:NonRiskRatedLoansMember2026-06-300000357173us-gaap:PerformingFinancingReceivableMemberus-gaap:HomeEquityMemberosbc:NonRiskRatedLoansMember2026-06-300000357173us-gaap:PerformingFinancingReceivableMemberosbc:RealEstateOwnerOccupiedMemberosbc:NonRiskRatedLoansMember2026-06-300000357173us-gaap:PerformingFinancingReceivableMemberosbc:PowersportPortfolioSegmentMemberosbc:NonRiskRatedLoansMember2026-06-300000357173us-gaap:NonperformingFinancingReceivableMemberus-gaap:UnallocatedFinancingReceivablesMemberosbc:NonRiskRatedLoansMember2026-06-300000357173us-gaap:NonperformingFinancingReceivableMemberus-gaap:HomeEquityMemberosbc:NonRiskRatedLoansMember2026-06-300000357173us-gaap:NonperformingFinancingReceivableMemberosbc:RealEstateOwnerOccupiedMemberosbc:NonRiskRatedLoansMember2026-06-300000357173us-gaap:NonperformingFinancingReceivableMemberosbc:PowersportPortfolioSegmentMemberosbc:NonRiskRatedLoansMember2026-06-300000357173us-gaap:UnallocatedFinancingReceivablesMemberus-gaap:SubstandardMember2026-06-300000357173us-gaap:UnallocatedFinancingReceivablesMemberus-gaap:PassMember2026-06-300000357173us-gaap:UnallocatedFinancingReceivablesMemberosbc:NonRiskRatedLoansMember2026-06-300000357173us-gaap:PerformingFinancingReceivableMemberosbc:NonRiskRatedLoansMember2026-06-300000357173us-gaap:NonperformingFinancingReceivableMemberosbc:NonRiskRatedLoansMember2026-06-300000357173us-gaap:HomeEquityMemberus-gaap:SubstandardMember2026-06-300000357173us-gaap:HomeEquityMemberus-gaap:PassMember2026-06-300000357173us-gaap:HomeEquityMemberosbc:NonRiskRatedLoansMember2026-06-300000357173us-gaap:FinanceLeasesPortfolioSegmentMemberus-gaap:SubstandardMember2026-06-300000357173us-gaap:FinanceLeasesPortfolioSegmentMemberus-gaap:SpecialMentionMember2026-06-300000357173us-gaap:FinanceLeasesPortfolioSegmentMemberus-gaap:PassMember2026-06-300000357173us-gaap:ConstructionMemberus-gaap:SubstandardMember2026-06-300000357173us-gaap:ConstructionMemberus-gaap:PassMember2026-06-300000357173us-gaap:CommercialPortfolioSegmentMemberus-gaap:SubstandardMember2026-06-300000357173us-gaap:CommercialPortfolioSegmentMemberus-gaap:SpecialMentionMember2026-06-300000357173us-gaap:CommercialPortfolioSegmentMemberus-gaap:PassMember2026-06-300000357173us-gaap:CommercialPortfolioSegmentMemberus-gaap:DoubtfulMember2026-06-300000357173osbc:RealEstateOwnerOccupiedMemberus-gaap:SubstandardMember2026-06-300000357173osbc:RealEstateOwnerOccupiedMemberus-gaap:PassMember2026-06-300000357173osbc:RealEstateOwnerOccupiedMemberosbc:NonRiskRatedLoansMember2026-06-300000357173osbc:RealEstateInvestorMemberus-gaap:SubstandardMember2026-06-300000357173osbc:RealEstateInvestorMemberus-gaap:PassMember2026-06-300000357173osbc:PowersportPortfolioSegmentMemberus-gaap:SubstandardMember2026-06-300000357173osbc:PowersportPortfolioSegmentMemberus-gaap:PassMember2026-06-300000357173osbc:PowersportPortfolioSegmentMemberosbc:NonRiskRatedLoansMember2026-06-300000357173osbc:MultiFamilyLoanMemberus-gaap:SubstandardMember2026-06-300000357173osbc:MultiFamilyLoanMemberus-gaap:PassMember2026-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:SubstandardMember2026-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:SpecialMentionMember2026-06-300000357173osbc:CommercialRealEstateOwnerOccupiedMemberus-gaap:PassMember2026-06-300000357173osbc:CommercialRealEstateInvestorMemberus-gaap:SubstandardMember2026-06-300000357173osbc:CommercialRealEstateInvestorMemberus-gaap:SpecialMentionMember2026-06-300000357173osbc:CommercialRealEstateInvestorMemberus-gaap:PassMember2026-06-300000357173us-gaap:SubstandardMember2026-06-300000357173us-gaap:SpecialMentionMember2026-06-300000357173us-gaap:PassMember2026-06-300000357173us-gaap:DoubtfulMember2026-06-300000357173osbc:Other2Member2026-06-300000357173osbc:NonRiskRatedLoansMember2026-06-300000357173us-gaap:PerformingFinancingReceivableMemberus-gaap:UnallocatedFinancingReceivablesMemberosbc:NonRiskRatedLoansMember2025-12-310000357173us-gaap:PerformingFinancingReceivableMemberus-gaap:HomeEquityMemberosbc:NonRiskRatedLoansMember2025-12-310000357173us-gaap:PerformingFinancingReceivableMemberosbc:PowersportPortfolioSegmentMemberosbc:NonRiskRatedLoansMember2025-12-310000357173us-gaap:PerformingFinancingReceivableMemberosbc:CommercialRealEstateOwnerOccupiedMemberosbc:NonRiskRatedLoansMember2025-12-310000357173us-gaap:NonperformingFinancingReceivableMemberus-gaap:UnallocatedFinancingReceivablesMemberosbc:NonRiskRatedLoansMember2025-12-310000357173us-gaap:NonperformingFinancingReceivableMemberus-gaap:HomeEquityMemberosbc:NonRiskRatedLoansMember2025-12-310000357173us-gaap:NonperformingFinancingReceivableMemberosbc:PowersportPortfolioSegmentMemberosbc:NonRiskRatedLoansMember2025-12-310000357173us-gaap:NonperformingFinancingReceivableMemberosbc:CommercialRealEstateOwnerOccupiedMemberosbc:NonRiskRatedLoansMember2025-12-310000357173us-gaap:UnallocatedFinancingReceivablesMemberus-gaap:SubstandardMember2025-12-310000357173us-gaap:UnallocatedFinancingReceivablesMemberus-gaap:PassMember2025-12-310000357173us-gaap:UnallocatedFinancingReceivablesMemberosbc:NonRiskRatedLoansMember2025-12-310000357173us-gaap:PerformingFinancingReceivableMemberosbc:NonRiskRatedLoansMember2025-12-310000357173us-gaap:NonperformingFinancingReceivableMemberosbc:NonRiskRatedLoansMember2025-12-310000357173us-gaap:HomeEquityMemberus-gaap:SubstandardMember2025-12-310000357173us-gaap:HomeEquityMemberus-gaap:PassMember2025-12-310000357173us-gaap:HomeEquityMemberosbc:NonRiskRatedLoansMember2025-12-310000357173us-gaap:FinanceLeasesPortfolioSegmentMemberus-gaap:SubstandardMember2025-12-310000357173us-gaap:FinanceLeasesPortfolioSegmentMemberus-gaap:SpecialMentionMember2025-12-310000357173us-gaap:FinanceLeasesPortfolioSegmentMemberus-gaap:PassMember2025-12-310000357173us-gaap:ConstructionMemberus-gaap:SubstandardMember2025-12-310000357173us-gaap:ConstructionMemberus-gaap:PassMember2025-12-310000357173us-gaap:CommercialPortfolioSegmentMemberus-gaap:SubstandardMember2025-12-310000357173us-gaap:CommercialPortfolioSegmentMemberus-gaap:SpecialMentionMember2025-12-310000357173us-gaap:CommercialPortfoli