XML 83 R67.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Loans and Allowance for Credit Losses on Loans - Charge-offs Activity by Loan Type (Details) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Loans by risk rating |  |  |
2023 | $ 123 |  |
2022 | 9,247 |  |
2021 | 742 |  |
2020 | 10,587 |  |
2019 | 3,524 |  |
Prior | 419 |  |
Total | 24,642 | $ 2,460 | $ 5,933
Commercial |  |  |
Loans by risk rating |  |  |
2021 | 466 |  |
2020 | 364 |  |
Prior | 55 |  |
Total | 885 | 151 | 963
Leases |  |  |
Loans by risk rating |  |  |
2022 | 870 |  |
2019 | 12 |  |
Total | 882 | 371 | 69
Commercial real estate - Investor |  |  |
Loans by risk rating |  |  |
2023 | 123 |  |
2022 | 8,352 |  |
2021 | 71 |  |
2020 | 3,270 |  |
Total | 11,816 | 1,401 | 2,724
Commercial real estate - Owner occupied |  |  |
Loans by risk rating |  |  |
2022 | 22 |  |
2021 | 178 |  |
2020 | 6,947 |  |
2019 | 3,512 |  |
Prior | 32 |  |
Total | 10,691 | 133 | 1,797
Residential real estate - Owner occupied |  |  |
Loans by risk rating |  |  |
Total |  | 2 |
Multifamily |  |  |
Loans by risk rating |  |  |
Total |  |  | 183
HELOC |  |  |
Loans by risk rating |  |  |
Total |  |  | 17
Other |  |  |
Loans by risk rating |  |  |
2022 | 3 |  |
2021 | 27 |  |
2020 | 6 |  |
Prior | 332 |  |
Total | $ 368 | $ 402 | $ 180

X
- Definition Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable and net investment in lease from write-off. + References No definition available. + Details
Name: | osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestAllowanceForCreditLossWriteoff
Namespace Prefix: | osbc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of writeoff of financing receivable and net investment in sales-type and direct financing leases originated in five years before current fiscal year. + References No definition available. + Details
Name: | osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff
Namespace Prefix: | osbc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of writeoff of financing receivable and net investment in sales-type and direct financing leases originated in four years before current fiscal year. + References No definition available. + Details
Name: | osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff
Namespace Prefix: | osbc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of writeoff of financing receivable and net investment in sales-type and direct financing leases originated in three years before current fiscal year. + References No definition available. + Details
Name: | osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff
Namespace Prefix: | osbc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of writeoff of financing receivable and net investment in sales-type and direct financing leases originated in current fiscal year. + References No definition available. + Details
Name: | osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearOneOriginatedCurrentFiscalYearWriteoff
Namespace Prefix: | osbc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of writeoff of financing receivable and net investment in sales-type and direct financing leases originated in two years before current fiscal year. + References No definition available. + Details
Name: | osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff
Namespace Prefix: | osbc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of writeoff of financing receivable and net investment in sales-type and direct financing leases originated in fiscal year before current fiscal year. + References No definition available. + Details
Name: | osbc_FinancingReceivableAndNetInvestmentInLeaseExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff
Namespace Prefix: | osbc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479319/326-20-50-5 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 79 -Publisher FASB -URI https://asc.fasb.org//1943274/2147479294/326-20-55-79 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_FinanceLeasesPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=osbc_CommercialRealEstateInvestorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=osbc_CommercialRealEstateOwnerOccupiedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=osbc_RealEstateOwnerOccupiedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=osbc_MultiFamilyLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_HomeEquityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_UnallocatedFinancingReceivablesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |