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, 2010	$ 3,158,791	$ 514,388	$ 1,739	$ 1,573,372	$ 1,041,666	$ 27,626	$ 0
Comprehensive (loss) income:
Net income (loss)	57,235	0	0	0	57,235	0	0
Other comprehensive income	51,719	0	0	0	0	51,719	0
Comprehensive income (loss)	108,954
Common stock issued:
Stock-based compensation plans, net	2,283	0	6	2,437	(113)	0	(47)
Purchase of treasury stock	(616)	0	0	0	0	0	(616)
Cash dividends:
Common stock	(3,487)	0	0	0	(3,487)	0	0
Preferred stock	(10,062)	0	0	0	(10,062)	0	0
Redemption of preferred stock	(262,500)	(262,500)	0	0	0	0	0
Proceeds from issuance of preferred stock	0
Accretion of preferred stock discount	0	6,163	0	0	(6,163)	0	0
Stock-based compensation expense, net	5,774	0	0	5,774	0	0	0
Tax benefit of stock options	11	0	0	11	0	0	0
Ending balance at Jun. 30, 2011	2,999,148	258,051	1,745	1,581,594	1,079,076	79,345	(663)
Beginning balance at Dec. 31, 2011	2,865,794	63,272	1,746	1,586,401	1,148,773	65,602	0
Comprehensive (loss) income:
Net income (loss)	85,950	0	0	0	85,950	0	0
Other comprehensive income	977	0	0	0	0	977	0
Comprehensive income (loss)	86,927
Common stock issued:
Stock-based compensation plans, net	145	0	4	650	(1,009)	0	500
Purchase of treasury stock	(31,210)	0	0	0	0	0	(31,210)
Cash dividends:
Common stock	(17,379)	0	0	0	(17,379)	0	0
Preferred stock	(2,600)	0	0	0	(2,600)	0	0
Proceeds from issuance of preferred stock	0
Stock-based compensation expense, net	7,939	0	0	7,939	0	0	0
Tax benefit of stock options	5	0	0	5	0	0	0
Ending balance at Jun. 30, 2012	$ 2,909,621	$ 63,272	$ 1,750	$ 1,594,995	$ 1,213,735	$ 66,579	$ (30,710)