EARNINGS (LOSS) PER COMMON SHARE (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share [Abstract]
Net income from continuing operations attributable to First Banks, Inc.	$ 5,231	$ 12,797	$ 10,636	$ 21,571
Preferred stock dividends declared	0	(4,947)	0	(9,828)
Accretion of discount on preferred stock	0	(908)	0	(1,806)
Net income from continuing operations attributable to common stockholders	5,231	6,942	10,636	9,937
Loss from discontinued operations, net of tax	0	(3,334)	0	(5,398)
Net income available to common stockholders	5,231	3,608	10,636	4,539
Effect of dilutive Securities - Class A convertible preferred stock	0	0	0	0
Diluted income available to First Banks, Inc. common stockholders	$ 5,231	$ 3,608	$ 10,636	$ 4,539
Weighted average shares of common stock outstanding (in shares)	23,661	23,661	23,661	23,661
Effect of dilutive securities – Class A convertible preferred stock (in shares)	3,903	0	4,162	0
Weighted average diluted shares of common stock outstanding (in shares)	27,564	23,661	27,823	23,661
Basic earnings per common share - continuing operations (in dollars per share)	$ 221.11	$ 293.39	$ 449.54	$ 419.98
Basic loss per common share - discontinued operations (in dollars per share)	$ 0.00	$ (140.90)	$ 0.00	$ (228.14)
Basic earnings per common share (in dollars per share)	$ 221.11	$ 152.49	$ 449.54	$ 191.84
Diluted earnings per common share - continuing operations (in dollars per share)	$ 189.80	$ 293.39	$ 382.26	$ 419.98
Diluted loss per common share - discontinued operations (in dollars per share)	$ 0.00	$ (140.90)	$ 0.00	$ (228.14)
Diluted earnings per common share (in dollars per share)	$ 189.80	$ 152.49	$ 382.26	$ 191.84