SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended												12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Selected Quarterly Financial Information [Abstract]
Interest income	$ 45,525	$ 47,174	$ 47,265	$ 47,198	$ 48,451	$ 49,561	$ 49,888	$ 49,663	$ 52,228	$ 54,250	$ 55,634	$ 55,970	$ 187,162	$ 197,563	$ 218,082
Interest expense	3,991	4,476	4,975	6,072	6,865	7,833	8,687	9,607	11,471	14,328	16,693	17,820	19,514	32,992	60,312
Net interest income before provision for loan losses	41,534	42,698	42,290	41,126	41,586	41,728	41,201	40,056	40,757	39,922	38,941	38,150	167,648	164,571	157,770
Provision for loan losses	1,000	3,000	4,000	5,000	5,000	5,000	8,000	17,000	20,000	20,000	16,000	14,000	13,000	35,000	70,000
Net interest income	40,534	39,698	38,290	36,126	36,586	36,728	33,201	23,056	20,757	19,922	22,941	24,150	154,648	129,571	87,770
Other operating income	13,311	11,684	(9,064)	10,971	7,151	10,340	9,253	7,246	7,586	7,652	6,186	7,724	26,902	33,990	29,148
Other operating expenses	34,519	33,355	35,666	37,913	38,667	41,038	40,255	38,144	41,034	46,328	38,024	35,415	141,453	158,104	160,801
Income (loss) before provision for (benefit from) income taxes	19,326	18,027	(6,440)	9,184	5,070	6,030	2,199	(7,842)	(12,691)	(18,754)	(8,897)	(3,541)	40,097	5,457	(43,883)
Provision (benefit) for income taxes	4,638	2,407	(31,830)	0	0	0	0	0	0	23,988	(3,951)	(2,024)	(24,785)	0	18,013
NET INCOME (LOSS)	14,688	15,620	25,390	9,184	5,070	6,030	2,199	(7,842)	(12,691)	(42,742)	(4,946)	(1,517)	64,882	5,457	(61,896)
Preferred stock dividend	611	1,227	1,550	1,550	1,550	1,550	1,550	1,550	1,550	1,550	1,550	1,550	4,938	6,200	6,200
Preferred stock discount accretion	1,174	1,216	454	454	425	425	425	426	398	398	399	398	3,298	1,701	1,593
Gain on repurchase and retirement of preferred stock	(401)	(2,070)	0	0									(2,471)	0	0
NET INCOME (LOSS) AVAILABLE TO COMMON SHAREHOLDERS	$ 13,304	$ 15,247	$ 23,386	$ 7,180	$ 3,095	$ 4,055	$ 224	$ (9,818)	$ (14,639)	$ (44,690)	$ (6,895)	$ (3,465)	$ 59,117	$ (2,444)	$ (69,689)
Basic earnings (loss) per share (in dollars per share)	$ 0.69	$ 0.80	$ 1.27	$ 0.40	$ 0.18	$ 0.24	$ 0.01	$ (0.61)	$ (0.91)	$ (2.80)	$ (1.96)	$ (1.12)	$ 3.17	$ (0.15)	$ (7.21)
Diluted earnings (loss) per share (in dollars per share)	$ 0.69	$ 0.79	$ 1.27	$ 0.40	$ 0.18	$ 0.24	$ 0.01	$ (0.61)	$ (0.91)	$ (2.80)	$ (1.96)	$ (1.12)	$ 3.16	$ (0.15)	$ (7.21)
Cumulative dividends declared per common share (in dollars per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.01	$ 0.07	$ 0.07	$ 0.07	$ 0.07	$ 0.07	$ 0.04	$ 0.10	$ 0.28