XML 77 R65.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Fair Value Measurements - Recurring (Details) - USD ($) $ in Thousands | 9 Months Ended |
--- | --- | ---
Sep. 30, 2017 | Dec. 31, 2016
Assets: |  |
Securities available-for-sale | $ 533,484 | $ 531,838
Mortgage servicing rights | 6,684 | 6,489
U.S. Treasury |  |
Assets: |  |
Securities available-for-sale | 3,990 |
U.S. government agencies |  |
Assets: |  |
Securities available-for-sale | 13,451 | 41,534
U.S. government agency mortgage-backed |  |
Assets: |  |
Securities available-for-sale | 11,030 |
States and political subdivisions |  |
Assets and liabilities measured at fair value on a recurring basis |  |
Purchases | 10,994 |
Assets: |  |
Securities available-for-sale | 229,032 | 68,703
Corporate bonds |  |
Assets: |  |
Securities available-for-sale | 10,577 | 10,630
Collateralized mortgage obligations |  |
Assets: |  |
Securities available-for-sale | 80,386 | 170,927
Asset-backed securities |  |
Assets: |  |
Securities available-for-sale | 131,759 | 138,407
Collateralized loan obligations |  |
Assets: |  |
Securities available-for-sale | 53,259 | 101,637
Level 1 |  |
Assets: |  |
Securities available-for-sale | 3,990 |
Level 2 |  |
Assets: |  |
Securities available-for-sale | 514,642 | 506,493
Loans held-for-sale | 1,641 | 4,918
Liabilities: |  |
Other liabilities | 1,439 | 994
Level 3 |  |
Assets: |  |
Securities available-for-sale | 14,852 | 25,345
Recurring |  |
Assets: |  |
Total financial assets | 542,226 | 544,205
Liabilities: |  |
Total | 1,566 | 1,667
Recurring | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Loans held-for-sale | 1,641 | 4,918
Mortgage servicing rights | 6,684 | 6,489
Recurring | Interest rate swap agreements net of swap credit valuation |  |
Liabilities: |  |
Other liabilities | 1,566 | 1,667
Recurring | Interest rate swap agreements net of swap credit valuation | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Other assets | 128 | 673
Recurring | Forward MBS contracts and forward loan contracts | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Other assets | 289 | 287
Recurring | U.S. Treasury | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 3,990 |
Recurring | U.S. government agencies | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 13,451 |
Recurring | U.S. government agency mortgage-backed | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 11,030 | 41,534
Recurring | States and political subdivisions | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 229,032 | 68,703
Recurring | Corporate bonds | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 10,577 | 10,630
Recurring | Collateralized mortgage obligations | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 80,386 | 170,927
Recurring | Asset-backed securities | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 131,759 | 138,407
Recurring | Collateralized loan obligations | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 53,259 | 101,637
Recurring | Level 1 |  |
Assets: |  |
Total financial assets | 3,990 |
Recurring | Level 1 | U.S. Treasury | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 3,990 |
Recurring | Level 2 |  |
Assets: |  |
Total financial assets | 516,700 | 512,371
Liabilities: |  |
Total | 1,566 | 1,667
Recurring | Level 2 | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Loans held-for-sale | 1,641 | 4,918
Recurring | Level 2 | Interest rate swap agreements net of swap credit valuation |  |
Liabilities: |  |
Other liabilities | 1,566 | 1,667
Recurring | Level 2 | Interest rate swap agreements net of swap credit valuation | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Other assets | 128 | 673
Recurring | Level 2 | Forward MBS contracts and forward loan contracts | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Other assets | 289 | 287
Recurring | Level 2 | U.S. government agencies | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 13,451 |
Recurring | Level 2 | U.S. government agency mortgage-backed | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 11,030 | 41,534
Recurring | Level 2 | States and political subdivisions | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 216,672 | 46,477
Recurring | Level 2 | Corporate bonds | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 10,577 | 10,630
Recurring | Level 2 | Collateralized mortgage obligations | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 77,894 | 167,808
Recurring | Level 2 | Asset-backed securities | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 131,759 | 138,407
Recurring | Level 2 | Collateralized loan obligations | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 53,259 | 101,637
Recurring | Level 3 |  |
Assets: |  |
Total financial assets | 21,536 | 31,834
Recurring | Level 3 | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Mortgage servicing rights | 6,684 | 6,489
Recurring | Level 3 | States and political subdivisions | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | 12,360 | 22,226
Recurring | Level 3 | Collateralized mortgage obligations | Finite-Lived Intangible Assets [Member] |  |
Assets: |  |
Securities available-for-sale | $ 2,492 | $ 3,119

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=75030427&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=82896770&loc=d3e26610-111562 + Details
Name: | us-gaap_AvailableForSaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13495-108611 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=82849420&loc=SL20226008-175313 + Details
Name: | us-gaap_DerivativeAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=82849420&loc=SL20226008-175313 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 15 -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13495-108611 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41271-113958 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 + Details
Name: | us-gaap_DerivativeLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Fair value of financial and nonfinancial obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
Name: | us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

X
- Definition Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables. + References No definition available. + Details
Name: | us-gaap_LoansHeldForSaleFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 50 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=68078379&loc=d3e122625-111746 + Details
Name: | us-gaap_ServicingAssetAtFairValueAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=osbc_MortgageBackedSecuritiesIssuedByUSGovernmentAgenciesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USStatesAndPoliticalSubdivisionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CorporateBondSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CollateralizedMortgageObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CollateralizedLoanObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_FiniteLivedIntangibleAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForwardContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |