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)	22,853	0	0	0	22,853	0	0
Other comprehensive income	18,105	0	0	0	0	18,105	0
Comprehensive income (loss)	40,958
Common stock issued:
Stock-based compensation plans, net	928	0	5	582	(20)	0	361
Purchase of treasury stock	(607)	0	0	0	0	0	(607)
Cash dividends:
Common stock	(1,742)	0	0	0	(1,742)	0	0
Preferred stock	(6,563)	0	0	0	(6,563)	0	0
Proceeds from issuance of preferred stock	0
Accretion of preferred stock discount	0	850	0	0	(850)	0	0
Stock-based compensation expense, net	2,947	0	0	2,947	0	0	0
Tax benefit of stock options	2	0	0	2	0	0	0
Ending balance at Mar. 31, 2011	3,194,714	515,238	1,744	1,576,903	1,055,344	45,731	(246)
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)	42,633	0	0	0	42,633	0	0
Other comprehensive income	(324)	0	0	0	0	(324)	0
Comprehensive income (loss)	42,309
Common stock issued:
Stock-based compensation plans, net	119	0	4	136	(124)	0	103
Purchase of treasury stock	(1,113)	0	0	0	0	0	(1,113)
Cash dividends:
Common stock	(8,735)	0	0	0	(8,735)	0	0
Preferred stock	(1,300)	0	0	0	(1,300)	0	0
Proceeds from issuance of preferred stock	0
Stock-based compensation expense, net	3,794	0	0	3,794	0	0	0
Tax benefit of stock options	5	0	0	5	0	0	0
Ending balance at Mar. 31, 2012	$ 2,900,873	$ 63,272	$ 1,750	$ 1,590,336	$ 1,181,247	$ 65,278	$ (1,010)