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 (Loss)	Treasury Stock
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	85,950	0	0	0	85,950	0	0
Other comprehensive income (loss)	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
Redemption of preferred stock	0	0	0	0	0	0	0
Issuance of preferred stock	0	0
Accretion of preferred stock discount	0	0	0	0	0	0	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)
Beginning balance at Dec. 31, 2012	2,936,399	63,272	1,750	1,602,136	1,281,811	48,603	(61,173)
Comprehensive (loss) income:
Net income	95,276	0	0	0	95,276	0	0
Other comprehensive income (loss)	(73,618)	0	0	0	0	(73,618)	0
Comprehensive income (loss)	21,658
Common stock issued:
Stock-based compensation plans, net	3,995	0	0	387	(16,793)	0	20,401
Purchase of treasury stock	(63,239)	0	0	0	0	0	(63,239)
Cash dividends:
Common stock	(26,957)	0	0	0	(26,957)	0	0
Preferred stock	(2,600)	0	0	0	(2,600)	0	0
Stock-based compensation expense, net	7,571	0	0	7,571	0	0	0
Tax benefit of stock options	149	0	0	149	0	0	0
Ending balance at Jun. 30, 2013	$ 2,876,976	$ 63,272	$ 1,750	$ 1,610,243	$ 1,330,737	$ (25,015)	$ (104,011)