XML 38 R27.htm IDEA: XBRL DOCUMENT
v3.23.1

Deposits (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2023
Deposits |
Schedule of major classifications of deposits | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​
​ |  | March 31, 2023 |  | December 31, 2022 |
Noninterest bearing demand | ​ | $ | 1,950,144 | ​ | $ | 2,051,702 | ​
Savings | ​ | ​ | 1,108,610 | ​ | ​ | 1,145,592 | ​
NOW accounts | ​ | ​ | 608,260 | ​ | ​ | 609,338 | ​
Money market accounts | ​ | ​ | 799,300 | ​ | ​ | 862,170 | ​
Certificates of deposit of less than $100,000 | ​ | ​ | 238,257 | ​ | ​ | 244,017 | ​
Certificates of deposit of $100,000 through $250,000 | ​ | ​ | 147,887 | ​ | ​ | 157,438 | ​
Certificates of deposit of more than $250,000 | ​ | ​ | 44,762 | ​ | ​ | 40,466 | ​
Total deposits | ​ | $ | 4,897,220 | ​ | $ | 5,110,723 | ​
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​

X
- Definition Tabular disclosure of different types of deposits liabilities held by the entity. + References No definition available. + Details
Name: | osbc_ScheduleOfDepositsTableTextBlock
Namespace Prefix: | osbc_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

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