XML 46 R59.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Fair Value Option and Fair Value Measurements - Quantitative and Qualitative Information (Details) (USD $) In Thousands, unless otherwise specified |  |  |  |  |  | 9 Months Ended |  | 9 Months Ended |  |  | 9 Months Ended
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Sep. 30, 2014 | Dec. 31, 2013 | Sep. 30, 2014 Recurring Level 3 | Dec. 31, 2013 Recurring Level 3 | Dec. 31, 2013 Recurring Interest rate swap agreements net of swap credit valuation Level 3 | Sep. 30, 2013 Recurring Interest rate swap agreements net of swap credit valuation Management estimate of credit risk exposure Level 3 | Sep. 30, 2013 Recurring Interest rate swap agreements net of swap credit valuation Management estimate of credit risk exposure Level 3 Minimum | Sep. 30, 2013 Recurring Interest rate swap agreements net of swap credit valuation Management estimate of credit risk exposure Level 3 Maximum | Sep. 30, 2013 Recurring Interest rate swap agreements net of swap credit valuation Management estimate of credit risk exposure Level 3 Weighted Average of Inputs | Sep. 30, 2013 Recurring Mortgage servicing rights Discounted Cash Flow Level 3 | Sep. 30, 2014 Recurring Mortgage servicing rights Discounted Cash Flow Level 3 | Sep. 30, 2014 Recurring Mortgage servicing rights Discounted Cash Flow Level 3 Minimum | Sep. 30, 2014 Recurring Mortgage servicing rights Discounted Cash Flow Level 3 Maximum | Sep. 30, 2014 Recurring Mortgage servicing rights Discounted Cash Flow Level 3 Weighted Average of Inputs | Sep. 30, 2013 Recurring Mortgage servicing rights Discounted Cash Flow Level 3 Weighted Average of Inputs | Sep. 30, 2014 Recurring Asset-backed securities Discounted Cash Flow Level 3 | Sep. 30, 2013 Recurring Asset-backed securities Discounted Cash Flow Level 3 | Sep. 30, 2014 Recurring Asset-backed securities Discounted Cash Flow Level 3 Minimum | Sep. 30, 2013 Recurring Asset-backed securities Discounted Cash Flow Level 3 Minimum | Sep. 30, 2014 Recurring Asset-backed securities Discounted Cash Flow Level 3 Maximum | Sep. 30, 2013 Recurring Asset-backed securities Discounted Cash Flow Level 3 Maximum | Sep. 30, 2014 Recurring Asset-backed securities Discounted Cash Flow Level 3 Weighted Average of Inputs | Sep. 30, 2013 Recurring Asset-backed securities Discounted Cash Flow Level 3 Weighted Average of Inputs
Quantitative information about Level 3 fair value measurements |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Mortgage servicing rights, fair value | $ 5,640 | $ 5,807 | $ 5,640 | $ 5,807 |  |  |  |  |  | $ 5,807 | $ 5,640 |  |  |  |  |  |  |  |  |  |  |  |
Other assets |  |  |  |  | (6) | 6 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset-backed securities |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 83,781 | $ 154,137 |  |  |  |  |  |
Discount rate (as a percent) |  |  |  |  |  |  |  |  |  | 10.20% |  | 10.00% | 30.75% | 10.30% | 10.20% |  |  |  |  |  |  |  |
Prepayment speed (as a percent) |  |  |  |  |  |  |  |  |  | 9.70% |  | 3.97% | 77.99% | 9.50% | 9.70% |  |  |  |  |  |  |  |
Credit risk rating & probability of default (as a percent) |  |  |  |  |  |  | 5.00% | 20.00% | 12.50% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Credit risk premium (as a percent) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0.80% | 1.10% | 1.20% | 1.50% | 1.00% | 1.20%
Liquidity Discount (as a percent) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4.00% | 4.50% | 4.30% | 5.10% | 4.20% | 4.90%

X
- Definition Represents the credit risk premium expressed as a percentage, used as an input to measure fair value. + References No definition available. + Details
Name: | osbc_FairValueInputsCreditRiskPremium
Namespace Prefix: | osbc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of credit risk rating and likelihood that a loan will not be repaid and instead default, used as an input to measure the fair value. + References No definition available. + Details
Name: | osbc_FairValueInputsCreditRiskRatingAndProbabilityOfDefault
Namespace Prefix: | osbc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the liquidity discount expressed as a percentage, used as an input to measure fair value. + References No definition available. + Details
Name: | osbc_FairValueInputsLiquidityDiscount
Namespace Prefix: | osbc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Investments in notes or bonds that are collateralized by a specific group of underlying assets owned by the issuer of the notes or bonds which are short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three-years ago does not become a cash equivalent when its remaining maturity is three months. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash Equivalents -URI http://asc.fasb.org/extlink&oid=6507016 + Details
Name: | us-gaap_AssetBackedSecuritiesAtCarryingValue
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 825 -SubTopic 10 -Section 50 -Paragraph 10 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35750535&loc=d3e13433-108611 Reference 2: 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 3: 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=35750535&loc=d3e13495-108611 Reference 4: 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=34720828&loc=SL20225862-175312 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 210 -SubTopic 20 -Section 55 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=36459792&loc=SL20226008-175313 + Details
Name: | us-gaap_DerivativeAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt. + 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 (bbb) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueInputsDiscountRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Rate at which loans or a loan portfolio are expected to prepay principal balances, used as an input to measure fair value. + 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 (bbb) -URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258 + Details
Name: | us-gaap_FairValueInputsPrepaymentRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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=7882072&loc=d3e122625-111746 + Details
Name: | us-gaap_ServicingAssetAtFairValueAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant