XML 60 R43.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Mortgage Banking Derivatives (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2015
Not designated | Mortgage Banking Derivatives |
Mortgage Banking Derivatives |
Schedule of net gain or loss recorded on derivative activity | These mortgage banking derivatives are not designated in hedge relationships using the accepted accounting for derivative instruments and hedging activities at December 31 (dollars in thousands):
|  | 2015 |  | 2014 |
Forward contracts: |  |  |  |  |  |  |
Notional amount |  | $ | 15,500 |  | $ | 14,000 |
Fair value |  |  | 484 |  |  | 615 |
Change in fair value |  |  | 21 |  |  | (79) |
Rate lock commitments: |  |  |  |  |  |  |
Notional amount |  | $ | 10,973 |  | $ | 10,876 |
Fair value |  |  | 502 |  |  | 509 |
Change in fair value |  |  | 167 |  |  | 222 |

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

X
- Definition Tabular disclosure of the location and amount of derivative instruments and nonderivative instruments designated as hedging instruments reported before netting adjustments, and the amount of gain (loss) on derivative instruments and nonderivative instruments designated and qualified as hedging instruments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5624171-113959 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4A -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5618551-113959 + Details
Name: | us-gaap_ScheduleOfDerivativeInstrumentsGainLossInStatementOfFinancialPerformanceTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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