CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (UNAUDITED) - USD ($) $ in Thousands	Total	First Banks, Inc. Stockholders’ Equity, Preferred Stock [Member]	First Banks, Inc. Stockholders’ Equity, Common Stock [Member]	First Banks, Inc. Stockholders’ Equity, Additional Paid-In Capital [Member]	First Banks, Inc. Stockholders’ Equity, Retained Earnings [Member]	First Banks, Inc. Stockholders’ Equity, Accumulated Other Comprehensive Income [Member]	Noncontrolling Interest [Member]
Balance, beginning of period at Dec. 31, 2013	$ 488,256	$ 13,373	$ 5,915	$ 324,913	$ 42,719	$ 7,502	$ 93,834
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	10,582				10,636		(54)
Other comprehensive income	7,390					7,390
Balance, end of period at Jun. 30, 2014	506,228	13,373	5,915	324,913	53,355	14,892	93,780
Balance, beginning of period at Dec. 31, 2014	512,444	13,373	5,915	324,913	64,374	10,111	93,758
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	15,413				15,386		27
Other comprehensive income	67					67
Balance, end of period at Jun. 30, 2015	$ 527,924	$ 13,373	$ 5,915	$ 324,913	$ 79,760	$ 10,178	$ 93,785