Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Calculations for basic and diluted earnings per common share
Net income (loss)	$ 42,633	$ 22,853
Preferred stock dividends and discount accretion	(1,300)	(7,413)
Net income (loss) available to common equity	41,333	15,440
Common shareholder dividends	(8,683)	(1,732)
Unvested share-based payment awards	(40)	(9)
Undistributed earnings	32,610	13,699
Undistributed earnings allocated to common shareholders	32,455	13,622
Undistributed Earnings Allocated To Unvested Share-Based Payment Awards	155	77
Undistributed earnings	32,610	13,699
Basic
Distributed earnings to common shareholders	8,683	1,732
Undistributed earnings to common shareholders	32,455	13,622
Total common shareholders earnings, basic	41,138	15,354
Diluted
Distributed earnings to common shareholders	8,683	1,732
Undistributed earnings to common shareholders	32,455	13,622
Total common shareholders earnings, diluted	$ 41,138	$ 15,354
Weighted average common shares outstanding	173,846,000	173,213,000
Effect of dilutive common stock awards	2,000	4,000
Diluted weighted average common shares outstanding	173,848,000	173,217,000
Basic earnings (loss) per common share	$ 0.24	$ 0.09
Diluted earnings (loss) per common share	$ 0.24	$ 0.09
Earnings Per Share (Textuals) [Abstract]
Number of antidilutive stock options excluded from the computation of diluted earnings per share	6,000,000	5,000,000