CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data	Total	Preferred Stock [Member]	Common Stock and Paid in Capital [Member]	(Accumulated Deficit) [Member]	Accumulated Other Comprehensive Income [Member]
Balance, beginning of the period at Dec. 31, 2010	$ 511,472	$ 119,000	$ 507,470	$ (115,348)	$ 350
Balance, beginning of the period, shares at Dec. 31, 2010		124,000	16,130,441
Net income	5,457			5,457
Change in valuation of securities - available-for-sale, net of income tax	1,685				1,685
Amortization of unrealized loss on tax exempt securities transferred from available-for-sale to held-to-maturity, net of income tax	16				16
Accretion of preferred stock	0	1,701		(1,701)
Accrual of dividends on preferred stock	(6,200)			(6,200)
Accrual of dividends on common stock	(1,673)			(1,673)
Proceeds from issuance of common stock for stockholder reinvestment program (in shares)			1,372,625
Proceeds from issuance of common stock for stockholder reinvestment program	21,556		21,556
Amortization of compensation related to restricted stock grant (in shares)			16,066
Amortization of compensation related to restricted stock grant	111		111
Amortization of compensation related stock options	25		25
Other	1	1
Balance, end of the period at Dec. 31, 2011	532,450	120,702	529,162	(119,465)	2,051
Balance, end of the period, shares at Dec. 31, 2011		124,000	17,519,132
Net income	50,194			50,194
Change in valuation of securities - available-for-sale, net of income tax	335				335
Amortization of unrealized loss on tax exempt securities transferred from available-for-sale to held-to-maturity, net of income tax	7				7
Accretion of preferred stock	0	2,124		(2,124)
Accrual of dividends on preferred stock	(4,327)			(4,327)
Repurchase of preferred stock (in shares)		(50,584)
Repurchase of preferred stock	(48,514)	(50,584)		2,070
Accrual of dividends on common stock	(560)			(560)
Proceeds from issuance of common stock for stockholder reinvestment program (in shares)			1,814,234
Proceeds from issuance of common stock for stockholder reinvestment program	36,314		36,314
Amortization of compensation related to restricted stock grant (in shares)			87,173
Amortization of compensation related to restricted stock grant	189		189
Amortization of compensation related stock options	7		7
Balance, end of the period at Sep. 30, 2012	$ 566,095	$ 72,242	$ 565,672	$ (74,212)	$ 2,393
Balance, end of the period, shares at Sep. 30, 2012		73,416	19,420,539