CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY AND COMPREHENSIVE INCOME (LOSS) (USD $)	Total	Preferred Stock [Member]	Common Stock [Member]	Common Stock Warrants [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comp. Income, net [Member]
Balances at Dec. 31, 2008	$ 627,298,396	$ 88,348,647	$ 23,762,124	$ 6,696,804	$ 417,040,974	$ 84,380,447	$ 7,069,400
Balances (in shares) at Dec. 31, 2008			23,762,124
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of employee common stock options, stock appreciation rights, common stock warrants and related tax benefits	1,032,849	0	123,754	0	909,095	0	0
Exercise of employee common stock options, stock appreciation rights, common stock warrants and related tax benefits (in shares)			123,754
Issuance of restricted common shares, net of forfeitures	0	0	292,473	0	(292,473)	0	0
Issuance of restricted common shares, net of forfeitures (in shares)			292,473
Restricted shares withheld for taxes	(66,815)	0	(3,632)	0	(63,183)	0	0
Restricted shares withheld for taxes (in shares)			(3,632)
Issuance of shares of common stock, net of offering costs	109,027,785	0	8,855,000	0	100,172,785	0	0
Issuance of shares of common stock, net of offering costs (in shares)	8,855,000		8,855,000
Cancellation of warrants previously issued to U.S. Treasury	0	0	0	(3,348,402)	3,348,402	0	0
Compensation expense for restricted shares	1,444,274	0	0	0	1,444,274	0	0
Compensation expense for stock options	1,806,729	0	0	0	1,806,729	0	0
Accretion on preferred stock discount	0	1,113,986	0	0	0	(1,113,986)
Preferred dividends paid	(4,393,751)	0	0	0	0	(4,393,751)	0
Comprehensive income (loss):
Net loss	(35,499,967)	0	0	0	0	(35,499,967)	0
Net unrealized holding gains on securities available-for-sale, net of taxes	370,681	0	0	0	0	0	370,681
Total comprehensive loss	(35,129,286)
Balances at Dec. 31, 2009	701,020,181	89,462,633	33,029,719	3,348,402	524,366,603	43,372,743	7,440,081
Balances (in shares) at Dec. 31, 2009			33,029,719
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of employee common stock options, stock appreciation rights, common stock warrants and related tax benefits	3,485,812	0	601,023	0	2,884,789	0	0
Exercise of employee common stock options, stock appreciation rights, common stock warrants and related tax benefits (in shares)			601,023
Issuance of restricted common shares, net of forfeitures	0	0	252,053	0	(252,053)	0	0
Issuance of restricted common shares, net of forfeitures (in shares)			252,053
Restricted shares withheld for taxes	(163,748)	0	(12,415)	0	(151,333)	0	0
Restricted shares withheld for taxes (in shares)			(12,415)
Compensation expense for restricted shares	2,303,720	0	0	0	2,303,720	0	0
Compensation expense for stock options	1,677,293	0	0	0	1,677,293	0	0
Accretion on preferred stock discount	0	1,326,049	0	0	0	(1,326,049)	0
Preferred dividends paid	(4,750,000)	0	0	0	0	(4,750,000)	0
Comprehensive income (loss):
Net loss	(24,300,492)	0	0	0	0	(24,300,492)	0
Net unrealized holding gains on securities available-for-sale, net of taxes	(1,815,481)	0	0	0	0	0	(1,815,481)
Total comprehensive loss	(26,115,973)	0	0	0	0	0	0
Balances at Dec. 31, 2010	677,457,285	90,788,682	33,870,380	3,348,402	530,829,019	12,996,202	5,624,600
Balances (in shares) at Dec. 31, 2010	33,870,380		33,870,380
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of employee common stock options, stock appreciation rights, common stock warrants and related tax benefits	1,178,482	0	163,829	0	1,014,653	0	0
Exercise of employee common stock options, stock appreciation rights, common stock warrants and related tax benefits (in shares)			163,829
Repurchase of preferred stock	(23,750,000)	(23,750,000)	0	0	0	0	0
Issuance of restricted common shares, net of forfeitures	0	0	299,715	0	(299,715)	0	0
Issuance of restricted common shares, net of forfeitures (in shares)			299,715
Issuance of salary stock units	776,818	0	54,526		722,292
Issuance of salary stock units (in shares)			54,526
Restricted shares withheld for taxes	(507,938)	0	(33,490)	0	(474,448)	0	0
Restricted shares withheld for taxes (in shares)			(33,490)
Compensation expense for restricted shares	3,239,677	0	0	0	3,239,677	0	0
Compensation expense for stock options	1,196,059	0	0	0	1,196,059	0	0
Accretion on preferred stock discount	0	2,058,146	0	0	0	(2,058,146)	0
Preferred dividends paid	(4,891,839)	0	0	0	0	(4,891,839)	0
Comprehensive income (loss):
Net loss	43,737,367	0	0	0	0	43,737,367	0
Net unrealized holding gains on securities available-for-sale, net of taxes	11,708,657	0	0	0	0	0	11,708,657
Total comprehensive loss	55,446,025	0	0	0	0	0	0
Balances at Dec. 31, 2011	$ 710,144,568	$ 69,096,828	$ 34,354,960	$ 3,348,402	$ 536,227,537	$ 49,783,584	$ 17,333,257
Balances (in shares) at Dec. 31, 2011	34,354,960		34,354,960