XML 40 R28.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Deposits (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2018
Deposits |
Schedule of major classifications of deposits |
|  | March 31, 2018 |  | December 31, 2017 |
Noninterest bearing demand |  | $ | 582,766 |  | $ | 572,404 |
Savings |  |  | 274,029 |  |  | 262,220 |
NOW accounts |  |  | 442,119 |  |  | 429,448 |
Money market accounts |  |  | 281,860 |  |  | 276,082 |
Certificates of deposit of less than $100,000 |  |  | 216,843 |  |  | 216,493 |
Certificates of deposit of $100,000 through $250,000 |  |  | 123,132 |  |  | 122,489 |
Certificates of deposit of more than $250,000 |  |  | 41,299 |  |  | 43,789 |
Total deposits |  | $ | 1,962,048 |  | $ | 1,922,925 |

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: | nonnum: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