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
Preferred stock shares outstanding, beginning balance at Dec. 31, 2011		65
Common stock shares outstanding, beginning balance at Dec. 31, 2011			174,591
Comprehensive (loss) income:
Net income	178,973	0	0	0	178,973	0	0
Other comprehensive income (loss)	(16,999)	0	0	0	0	(16,999)	0
Comprehensive income	161,974
Common stock issued:
Stock-based compensation plans, net	145	0	4	761	(1,101)	0	481
Stock-based compensation plans, net shares issued		0	422
Purchase of treasury stock	(61,654)	0	0	0	0	0	(61,654)
Cash dividends:
Common stock	(39,634)	0	0	0	(39,634)	0	0
Preferred stock	(5,200)	0	0	0	(5,200)	0	0
Stock-based compensation expense, net	15,759	0	0	15,759	0	0	0
Tax impact of stock-based compensation	(785)	0	0	(785)	0	0	0
Ending balance at Dec. 31, 2012	2,936,399	63,272	1,750	1,602,136	1,281,811	48,603	(61,173)
Preferred stock shares outstanding, ending balance at Dec. 31, 2012		65
Common stock shares outstanding, ending balance at Dec. 31, 2012			175,013
Comprehensive (loss) income:
Net income	188,692	0	0	0	188,692	0	0
Other comprehensive income (loss)	(72,847)	0	0	0	0	(72,847)	0
Comprehensive income	115,845
Common stock issued:
Stock-based compensation plans, net	9,305	0	0	989	(17,630)	0	25,946
Stock-based compensation plans, net shares issued		0	0
Purchase of treasury stock	(123,349)	0	0	0	0	0	(123,349)
Cash dividends:
Common stock	(54,991)	0	0	0	(54,991)	0	0
Preferred stock	(5,158)	0	0	0	(5,158)	0	0
Issuance of preferred stock, shares		0	0
Purchase of preferred stock	(1,626)	(1,410)	0	0	(216)	0	0
Purchase of preferred stock, shares		(1)	0
Stock-based compensation expense, net	14,840	0	0	14,840	0	0	0
Tax impact of stock-based compensation	25	0	0	25	0	0	0
Ending balance at Dec. 31, 2013	2,891,290	61,862	1,750	1,617,990	1,392,508	(24,244)	(158,576)
Preferred stock shares outstanding, ending balance at Dec. 31, 2013		64
Common stock shares outstanding, ending balance at Dec. 31, 2013			175,013
Comprehensive (loss) income:
Net income	190,509	0	0	0	190,509	0	0
Other comprehensive income (loss)	19,394	0	0	0	0	19,394	0
Comprehensive income	209,903
Common stock issued:
Stock-based compensation plans, net	13,228	0	0	2,553	(21,171)	0	31,846
Stock-based compensation plans, net shares issued		0	0
Purchase of treasury stock	(112,312)	0	0	0	0	0	(112,312)
Cash dividends:
Common stock	(58,710)	0	0	0	(58,710)	0	0
Preferred stock	(5,002)	0	0	0	(5,002)	0	0
Purchase of common stock returned to authorized but unissued	(150,498)	0	(85)	(150,413)	0	0	0
Purchase of common stock returned to authorized but unissued, shares		0	(8,469)
Purchase of preferred stock	(2,451)	(2,135)	0	0	(316)	0	0
Purchase of preferred stock, shares		(2)	0
Stock-based compensation expense, net	16,091	0	0	16,091	0	0	0
Tax impact of stock-based compensation	(1,288)			(1,288)
Ending balance at Dec. 31, 2014	$ 2,800,251	$ 59,727	$ 1,665	$ 1,484,933	$ 1,497,818	$ (4,850)	$ (239,042)
Preferred stock shares outstanding, ending balance at Dec. 31, 2014		62
Common stock shares outstanding, ending balance at Dec. 31, 2014			166,544