Stockholders' Equity (Details) (USD $)	0 Months Ended	12 Months Ended
	Sep. 09, 2011 investors	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Class of Stock [Line Items]
Stockholders Equity, Subsidiaries		$ 552,236,000	$ 514,467,000	$ 454,408,000	$ 463,785,000
Stockholders' Equity restricted from dividend distribution		561,565,000
Dividend reinvestment and stock purchase plan, Stockholder's maximum amount of cash payments per quarter in purchase of common stock		2,500
Common stock number of investors in purchase securities agreement	2
Number of new stock issued during the period (shares)	2,822,000
Proceeds from Issuance of Common Stock	21,165,000
Sale of stock (usd per share)	$ 7.50
Subsidiaries
Class of Stock [Line Items]
Amount Available for Dividend Distribution without Affecting Capital Adequacy Requirements		70,704,000
Stockholders Equity, Subsidiaries		$ 632,269,000