XML 39 R24.htm IDEA: XBRL DOCUMENT
v3.22.4

Mortgage Banking Derivatives | 12 Months Ended
--- | ---
Dec. 31, 2022
Mortgage Banking Derivatives. |
Mortgage Banking Derivatives |
Mortgage Banking Derivatives | Note 16: Mortgage Banking Derivatives ​ Commitments to fund certain mortgage loans (interest rate locks) to be sold into the secondary market and forward commitments for the future delivery of mortgage loans to third party investors are considered derivatives. It is the Company’s practice to sell mortgage-backed securities (“MBS”) contracts for the future delivery to economically hedge the effect of changes in interest rates resulting from its commitments to fund the loans. These contracts are also derivatives and collectively with the forward commitments for the future delivery of mortgage loans are considered forward contracts. These mortgage banking derivatives, which are not designated in hedge relationships using the accepted accounting for derivative instruments and hedging activities at December 31, were as follows: ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ |  | 2022 |  | 2021 |
Forward contracts: | ​ | ​ | ​ | ​ | ​ | ​ | ​
Notional amount | ​ | $ | 2,750 | ​ | $ | 20,000 | ​
Fair value | ​ |  | 20 | ​ |  | 17 | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
Rate lock commitments: | ​ | ​ | ​ | ​ | ​ | ​ | ​
Notional amount | ​ | $ | 2,548 | ​ | $ | 14,414 | ​
Fair value | ​ |  | 56 | ​ |  | 491 | ​
​ Fair values were estimated based on changes in mortgage interest rates from the date of the commitments. The Company sold $76.6 million in loans to investors receiving proceeds of $81.8 million and resulting in a gain on sale of $2.0 million for the year ended December 31, 2022. Sales to investors included $62.4 million, or 76.5% to FNMA and $7.9 million, or 9.7%, to FHLMC for the year ended December 31, 2022. No other individual investor was sold more than 10% of the total loans sold.

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 The entire disclosure for derivative instruments and hedging activities including, but not limited to, risk management strategies, non-hedging derivative instruments, assets, liabilities, revenue and expenses, and methodologies and assumptions used in determining the amounts. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -URI https://asc.fasb.org/topic&trid=2229140 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 50 -Paragraph 5 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=126731327&loc=d3e90205-114008 + Details
Name: | us-gaap_DerivativeInstrumentsAndHedgingActivitiesDisclosureTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

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