XML 72 R61.htm IDEA: XBRL DOCUMENT
v3.22.1

Regulatory & Capital Matters - Dividend Restrictions and Deferrals (Details) | 3 Months Ended
--- | ---
Mar. 31, 2022
Dividend Restrictions and Deferrals |
Number of previous years retained profit considered for dividend payment | 2 years
Minimum capital requirements, minimum percentage required | 2.50%

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

X
- Definition Represents the number of previous years retained profits combined with the current years profits used to determine the amount of dividends that may be paid in any calendar year. + References No definition available. + Details
Name: | osbc_DividendRestrictionsNumberOfPreviousYearsRetainedProfit
Namespace Prefix: | osbc_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The minimum percentage of Tier 1 Common Capital required to be maintained in the next fiscal year following the latest fiscal year to prevent capital distribution limitations under regulatory capital rules. + References No definition available. + Details
Name: | osbc_TierOneCommonEquityCapitalDistributionLimitationMinimumRegulatoryCapitalPercentageNextTwelveMonths
Namespace Prefix: | osbc_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration