Note 3 - Cash and Due from Banks (Details Textual) - USD ($)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Amount of Required Reserve Balance with Federal Reserve Bank	$ 0	$ 0

Amount of reserve balance required to maintain with the Federal Reserve Bank (FRB).

No definition available.

Name:	ffbw_AmountOfRequiredReserveBalanceWithFederalReserveBank
Namespace Prefix:	ffbw_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration