Summary of Significant Accounting Policies (Narrative) (Details) - USD ($)		12 Months Ended
	Jan. 16, 2020	Dec. 31, 2019	Dec. 31, 2018
Common stock, outstanding (in shares)		6,566,478	6,696,742
Public offering costs		$ 603,000
Unrecognized tax benefits, income tax penalties and interest expense		0
Income tax expense (benefit), Total		$ 502,000	$ 318,000
Owned by Public [Member]
Common stock, outstanding (in shares)		2,929,603
Percentage of common stock outstanding to eligible Members		44.60%
Subsequent Event [Member]
Stock issued during period, shares	4,268,570
Issuance of common stock, net of issuance costs	$ 41,500,000
Sale of stock, price per share	$ 10.00
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Gain on Sale of Securities [Member]
Income tax expense (benefit), Total		$ 1,000	$ 56,000
FFBW Community Foundation [Member]
Common stock, outstanding (in shares)		25,000
FFBW, MHC [Member]
Common stock, outstanding (in shares)		3,636,875
Percentage of shares held by Mutual Holding Company		$ 55.4
FFBW, MHC [Member] | Subsequent Event [Member]
Stock issued during period, shares	3,436,430