Note 24 - First US Bancshares, Inc. (Parent Company Only) Financial Information - Statements of Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash on deposit	$ 49,599	$ 27,124	$ 23,530
Investment in subsidiaries	5	5
Other assets	7,954	8,372
Total assets	791,939	625,581
Other liabilities	6,826	6,319
Shareholders’ equity	79,437	76,208	76,241
Total liabilities and shareholders’ equity	791,939	625,581
FUSB [Member]
Cash on deposit	265	359	$ 226
Investment in subsidiaries	79,097	75,628
Other assets	326	121
Total assets	79,688	76,108
Other liabilities	251
Other liabilities		(99)
Shareholders’ equity	79,437	76,207
Total liabilities and shareholders’ equity	$ 79,688	$ 76,108