PARENT COMPANY ONLY FINANCIAL INFORMATION (Condensed Statements of Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Expense:
Interest	$ 21,178us-gaap_InterestExpense	$ 24,104us-gaap_InterestExpense	$ 29,611us-gaap_InterestExpense
Benefit for income taxes	12,159us-gaap_IncomeTaxExpenseBenefit	(288,501)us-gaap_IncomeTaxExpenseBenefit	(139)us-gaap_IncomeTaxExpenseBenefit
Net income attributable to First Banks, Inc.	21,655us-gaap_NetIncomeLoss	241,744us-gaap_NetIncomeLoss	26,278us-gaap_NetIncomeLoss
First Banks, Inc. Parent Company [Member]
Income:
Dividends from subsidiaries	95,000	0	0
Management fees from subsidiaries	9	23	3
Other	498	458	535
Total income	95,507	481	538
Expense:
Interest	12,935	15,054	14,847
Other	690	933	1,506
Total expense	13,625	15,987	16,353
Income (loss) before benefit for income taxes and equity in undistributed (losses) earnings of subsidiaries	81,882	(15,506)	(15,815)
Benefit for income taxes	(2,565)	(38,841)	(348)
Income (loss) before equity in undistributed (losses) earnings of subsidiaries	84,447	23,335	(15,467)
Equity in undistributed (losses) earnings of subsidiaries	(62,792)	218,409	41,745
Net income attributable to First Banks, Inc.	$ 21,655	$ 241,744	$ 26,278

Cash dividends received from consolidated subsidiaries.

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Total costs of sales and operating expenses for the period.

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