XML 90 R75.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Junior Subordinated Debentures - Issuance (Details) |  |  |  | 1 Months Ended | 6 Months Ended | 7 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 31, 2020 USD ($) | Mar. 02, 2020 USD ($) $ / shares | Feb. 24, 2020 USD ($) | Apr. 30, 2007 USD ($) | Jun. 15, 2017 | Dec. 31, 2017 | Dec. 31, 2021 USD ($) | Dec. 31, 2020 USD ($) item | Dec. 31, 2019 USD ($) | Jun. 16, 2017
Junior subordinated debentures |  |  |  |  |  |  |  |  |  |
Cash distribution rate of trust preferred securities (as a percent) |  |  | 7.80% |  |  |  |  |  |  |
Junior subordinated debentures | $ 25,773,000 |  |  |  |  |  | $ 25,773,000 | $ 25,773,000 |  |
Junior Subordinated Debentures issuance cost | 1,000 |  |  |  |  |  | $ 1,000 | 1,000 |  |
Cash disbursed for redemption |  | $ 33,000,000.0 |  |  |  |  |  |  |  |
Redemption price per share | $ / shares |  | $ 10.13 |  |  |  |  |  |  |  |
Proceeds from term note | 20,000,000.0 |  | $ 20,000,000.0 |  |  |  |  |  |  |
Unamortized debt issuance costs |  | $ 635,000 |  |  |  |  |  | $ 643,000 | $ 48,000 |
Old Second Capital Trust II [Member] |  |  |  |  |  |  |  |  |  |
Junior subordinated debentures |  |  |  |  |  |  |  |  |  |
Proceeds from sale of cumulative trust preferred securities |  |  |  | $ 25,000,000.0 |  |  |  |  |  |
Maturity Period |  |  |  |  |  |  | 30 years |  |  |
Cash distribution fixed rate of trust preferred securities (as a percent) |  |  |  |  | 6.77% |  |  |  |  |
Basis points added to cash distribution floating rate base (as a percent) |  |  |  |  |  | 1.50% |  |  |  |
Cash distribution, floating rate base |  |  |  |  |  |  | three-month LIBOR |  |  |
Term Debt |  |  |  |  |  |  |  |  |  |
Junior subordinated debentures |  |  |  |  |  |  |  |  |  |
Proceeds from term note | $ 13,000,000.0 |  | $ 20,000,000.0 |  |  |  |  |  |  |
Junior subordinated debentures |  |  |  |  |  |  |  |  |  |
Junior subordinated debentures |  |  |  |  |  |  |  |  |  |
Interest Payment Deferment Period | item |  |  |  |  |  |  |  | 20 |  |
Junior subordinated debentures | Old Second Capital Trust I |  |  |  |  |  |  |  |  |  |
Junior subordinated debentures |  |  |  |  |  |  |  |  |  |
Cash distribution rate of trust preferred securities (as a percent) |  | 7.80% |  |  |  |  |  |  |  |
Junior subordinated debentures |  | $ 32,600,000 |  |  |  |  |  |  |  |
Amortization period |  | 30 years |  |  |  |  |  |  |  |
Junior subordinated debentures | Old Second Capital Trust II [Member] |  |  |  |  |  |  |  |  |  |
Junior subordinated debentures |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) | 4.40% |  |  |  |  |  | 4.40% | 4.40% |  | 2.80%
Junior subordinated debentures |  |  |  |  |  |  | $ 25,800,000 |  |  |
7.8% subordinated debentures |  |  |  |  |  |  |  |  |  |
Junior subordinated debentures |  |  |  |  |  |  |  |  |  |
Interest rate (as a percent) |  | 7.80% |  |  |  |  |  |  |  |

X
- Definition The period up to which the interest payments may be deferred. + References No definition available. + Details
Name: | osbc_InterestPaymentDefermentPeriod
Namespace Prefix: | osbc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage points added to the reference rate to compute the variable rate on the trust preferred securities. + References No definition available. + Details
Name: | osbc_TrustPreferredSecuritiesBasisSpreadOnVariableRate
Namespace Prefix: | osbc_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the fixed annual rate of cash distributions on the securities. + References No definition available. + Details
Name: | osbc_TrustPreferredSecuritiesCashDistributionFixedRatePercentage
Namespace Prefix: | osbc_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the annual rate of cash distributions on the securities, which are payable quarterly. + References No definition available. + Details
Name: | osbc_TrustPreferredSecuritiesCashDistributionRatePercentage
Namespace Prefix: | osbc_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The reference rate for the variable rate of the trust preferred securities, such as LIBOR or the US treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR. + References No definition available. + Details
Name: | osbc_TrustPreferredSecuritiesDescriptionOfVariableRateBasis
Namespace Prefix: | osbc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the amortization period of the costs associated with the issuance of the trust preferred securities. + References No definition available. + Details
Name: | osbc_TrustPreferredSecuritiesIssuanceCostAmortizationPeriod
Namespace Prefix: | osbc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the maturity period of trust preferred securities. + References No definition available. + Details
Name: | osbc_TrustPreferredSecuritiesMaturityPeriod
Namespace Prefix: | osbc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of amortization expense attributable to debt issuance costs. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(8)) -URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1F -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495355-112611 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28555-108399 + Details
Name: | us-gaap_AmortizationOfFinancingCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

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 No definition available. + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1D -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28555-108399 + Details
Name: | us-gaap_DeferredFinanceCostsNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Including the current and noncurrent portions, the carrying value of junior subordinated long-term debt owed to unconsolidated subsidiary trusts as of the balance sheet date. Such debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets and was initially scheduled to be repaid after one year or beyond the normal operating cycle if longer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 + Details
Name: | us-gaap_JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The cash outflow to reacquire preferred stocks issued by a business trust or other special purpose entity, mainly established by a bank holding entity, to third party investors. The trust's assets are deeply subordinated debentures of the bank holding entity. Most trust preferred securities are subject to a mandatory redemption upon the repayment of the debentures. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3291-108585 + Details
Name: | us-gaap_PaymentsForRepurchaseOfTrustPreferredSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The price per share at which the preferred stock of an entity that has priority over common stock in the distribution of dividends and in the event of liquidation of the entity is redeemed or may be called at. The redemption features of this preferred stock are solely within the control of the issuer. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21488-112644 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21475-112644 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21564-112644 + Details
Name: | us-gaap_PreferredStockRedemptionPricePerShare
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cash inflow from issuance of preferred stocks by a business trust or other special purpose entity, mainly established by a bank holding entity, to third party investors. The trust's assets are deeply subordinated debentures of the bank holding entity. Most trust preferred securities are subject to a mandatory redemption upon the repayment of the debentures. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfTrustPreferredSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(f)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 + Details
Name: | us-gaap_ProceedsFromLinesOfCredit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=osbc_OldSecondCapitalTrustIIMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=osbc_TermDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_JuniorSubordinatedDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=osbc_OldSecondCapitalTrustIMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=osbc_SevenPointEightSubordinatedDebenturesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |