Consolidated Statements of Changes in Stockholder's Equity (Unaudited) (USD $) In Thousands, unless otherwise specified	Total	Preferred Equity	Common Stock	Surplus	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock
Beginning balance at Dec. 31, 2008	$ 2,876,503	$ 508,008	$ 1,281	$ 1,073,218	$ 1,293,941	$ 55	$ 0
Common stock shares outstanding, beginning balance at Dec. 31, 2008			128,116
Preferred stock shares outstanding, beginning balance at Dec. 31, 2008		525
April 1, 2009 adjustment for adoption of accounting standard related to other-than-temporary impairment					9,745	(9,745)
Comprehensive (loss) income:
Net income (loss)	(131,859)				(131,859)
Other comprehensive income (loss)	73,122					73,122
Comprehensive income (loss)	(58,737)
Common stock issued:
Issuance of common stock, shares			312
Stock-based compensation plans, net	81		3	1,157	(972)		(107)
Purchase of treasury stock	(599)						(599)
Cash dividends:
Common stock	(60,350)				(60,350)
Preferred stock	(26,250)				(26,250)
Issuance of preferred stock, shares			312
Accretion of preferred stock discount		3,099			(3,099)
Stock-based compensation expense, net	7,959			7,959
Tax impact of stock-based compensation	1			1
Ending balance at Dec. 31, 2009	2,738,608	511,107	1,284	1,082,335	1,081,156	63,432	(706)
Preferred stock shares outstanding, ending balance at Dec. 31, 2009		525
Common stock shares outstanding, ending balance at Dec. 31, 2009			128,428
Comprehensive (loss) income:
Net income (loss)	(856)				(856)
Other comprehensive income (loss)	(35,806)					(35,806)
Comprehensive income (loss)	(36,662)
Common stock issued:
Issuance of common stock, shares			44,843
Issuance of common stock, value	478,358		448	477,910
Stock-based compensation plans, net	3,468		7	4,080	(2,155)		1,536
Stock-based compensation plans, net shares issued	616
Purchase of treasury stock	(830)						(830)
Cash dividends:
Common stock	(6,948)				(6,948)
Preferred stock	(26,250)				(26,250)
Issuance of preferred stock	478,358		448	477,910
Issuance of preferred stock, shares			44,843
Accretion of preferred stock discount		3,281			(3,281)
Stock-based compensation expense, net	9,036			9,036
Tax impact of stock-based compensation	11			11
Ending balance at Dec. 31, 2010	3,158,791	514,388	1,739	1,573,372	1,041,666	27,626	0
Preferred stock shares outstanding, ending balance at Dec. 31, 2010		525
Common stock shares outstanding, ending balance at Dec. 31, 2010			173,887
Comprehensive (loss) income:
Net income (loss)	139,699				139,699
Other comprehensive income (loss)	37,976					37,976
Comprehensive income (loss)	177,675
Common stock issued:
Issuance of common stock, shares		65
Issuance of common stock, value	63,272	63,272
Stock-based compensation plans, net	4,231		7	4,350	(785)		659
Stock-based compensation plans, net shares issued			704
Purchase of treasury stock	(659)						(659)
Cash dividends:
Common stock	(6,977)				(6,977)
Preferred stock	(14,218)				(14,218)
Redemption of preferred stock	(525,000)	(525,000)
Redemption of preferred stock, shares		(525)
Issuance of preferred stock	63,272	63,272
Issuance of preferred stock, shares		65
Accretion of preferred stock discount	0	10,612			(10,612)
Stock-based compensation expense, net	11,024			11,024
Tax impact of stock-based compensation	(2,345)			(2,345)
Ending balance at Dec. 31, 2011	$ 2,865,794	$ 63,272	$ 1,746	$ 1,586,401	$ 1,148,773	$ 65,602	$ 0
Preferred stock shares outstanding, ending balance at Dec. 31, 2011		65
Common stock shares outstanding, ending balance at Dec. 31, 2011			174,591