Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) - shares	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Statement of Stockholders' Equity [Abstract]
ESOP shares committed to be released	4,906	4,918	9,811	9,782
Repurchase and cancellation of common stock-stock repurchase program	66,756	14,400	136,404	27,303

Adjustments to additional paid in capital, repurchase and cancellation of common stock-stock repurchase program, shares.

No definition available.

Name:	bcow_AdjustmentsToAdditionalPaidInCapitalRepurchaseAndCancellationOfCommonStockStockRepurchaseProgramShares
Namespace Prefix:	bcow_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration