Preferred Stock (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended		3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended
	Mar. 12, 2010	Mar. 31, 2013 item	Dec. 31, 2012	Mar. 31, 2013 Minimum item	Mar. 20, 2009 Series A senior preferred stock	Mar. 31, 2013 Series A senior preferred stock	Mar. 12, 2010 Series C preferred stock	Mar. 31, 2013 Series C preferred stock
Preferred Stock
Preferred stock, shares authorized		5,000,000	5,000,000
Number of series of preferred stock				1
Issuance of stock (in shares)					21,000		1,189,538
Value of stock issued to U.S. Treasury under CPP					$ 21.0
Liquidation preference per share					$ 1,000
Coupon rate for five years (as a percent)						5.00%
Coupon rate thereafter (as a percent)						9.00%
Percentage of liquidation preference amount at which the stock may be redeemed						100.00%
Period of redemption from the date of issue						3 years
Warrants issued as a percentage of preferred equity issuance amount						15.00%
Value of warrants issued to U.S. Treasury to purchase shares of common stock						3.2
Issuance of warrants (in shares)						611,650
Exercise price of warrants outstanding (in dollars per share)						$ 5.15
Expiration period of warrants issued						10 years
Gross proceeds from private placement	60.0						3.6
Preferred stock conversion ratio								1
Stated dividend rate (as a percent)								0.00%
Conversion price (in dollars per share)								$ 3.25
Value of contingent beneficial conversion feature to be recognized upon conversion								$ 0.2
Number of investors having board observation rights		2
Number of investors having board nomination rights		1