Participation in U.S. Treasury Capital Purchase Program (Details) (USD $)	0 Months Ended		1 Months Ended	3 Months Ended	12 Months Ended		0 Months Ended	12 Months Ended			0 Months Ended	12 Months Ended
	Jun. 23, 2011	May 06, 2011	Oct. 31, 2012	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2011	Jan. 16, 2009 Series T Preferred Stock	Dec. 31, 2012 Series T Preferred Stock	Dec. 31, 2012 Series T Preferred Stock Minimum	Dec. 31, 2012 Series T Preferred Stock Maximum	Jul. 24, 2009 Series T-ACB Preferred Stock	Dec. 31, 2012 Series T-ACB Preferred Stock
Class of Stock [Line Items]
Number of shares issued in Private Placement (in shares)	151,681	3,081,867				3,233,548	36,000
Preferred stock, liquidation preference per share							$ 1,000
Issuance of common stock					$ 42,472,000	$ 6,402,000	$ 36,000,000				$ 13,300,000
Warrants, number of securities called by warrants							385,990				273,534
Warrants, exercise price of warrants							13.99				7.30
Warrants, duration for which warrants exercisable							10 years				10 years
Dividends, preferred stock, cumulative quarterly dividends, percent per annum, first five years								5.00%				5.00%
Dividends, preferred stock, cumulative quarterly dividends, percent per annum, after five years								9.00%				9.00%
Warrants, fair value per share							$ 2.38
Fair Value of warrants (Black Scholes), Fair Value							900,000
Relative value, warrants, measured using relative fair value approach							1,700,000
Preferred stock, accretion of discount on shares									300,000	400,000
Common stock, par value				$ 1	$ 1	$ 1
Preferred stock converted to common shares			20,900,000
Discount accreted in period				856,000
Projected accretion, 2013				387,197	387,197
Projected accretion, 2014				$ 75,397	$ 75,397