Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Calculations for basic and diluted earnings per common share
Net income (loss)	$ 178,973	$ 139,699	$ (856)
Preferred stock dividends and discount accretion	(5,200)	(24,830)	(29,531)
Net income (loss) available to common equity	173,773	114,869	(30,387)
Common shareholder dividends	(39,462)	(6,935)	(6,918)
Unvested share-based payment awards	(172)	(42)	(30)
Undistributed earnings	134,139	107,892	(37,335)
Undistributed earnings allocated to common shareholders	133,549	107,231	(37,335)
Undistributed earnings allocated to unvested share-based payment awards	590	661	0
Undistributed earnings	134,139	107,892	(37,335)
Basic
Distributed earnings to common shareholders	39,462	6,935	6,918
Undistributed earnings to common shareholders	133,549	107,231	(37,335)
Common Shareholders Earnings Basic	173,011	114,166	(30,417)
Diluted
Distributed earnings to common shareholders	39,462	6,935	6,918
Undistributed earnings to common shareholders	133,549	107,231	(37,335)
Common Shareholders Earnings Diluted	$ 173,011	$ 114,166	$ (30,417)
Weighted average common shares outstanding	172,255,000	173,370,000	171,230,000
Effect of dilutive common stock awards	102,000	2,000	0
Diluted weighted average common shares outstanding	172,357,000	173,372,000	171,230,000
Basic earnings (loss) per common share	$ 1.00	$ 0.66	$ (0.18)
Diluted earnings (loss) per common share	$ 1.00	$ 0.66	$ (0.18)
Earnings Per Share (Textuals) [Abstract]
Number of antidilutive stock options excluded from the computation of diluted earnings per share	9,000,000	8,000,000