Preferred Stock Preferred Stock- Additional Information (Details) (USD $)			3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Series C Noncumulative Perpetual Preferred Stock
Class of Stock [Line Items]
Preferred stock, par value (usd per share)	$ 0.01	$ 0.01
Preferred stock Redemption period, following a regulatory capital treatment event			90 days