Consolidated Statements Of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Common Stock Held In Treasury [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance at Dec. 31, 2013	$ 1,628,811	$ 150	$ 1,377,624	$ (2,179,744)	$ 2,463,648	$ (32,867)
Balance, shares at Dec. 31, 2013		150,224		(70,704)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	149,654				149,654
Other comprehensive loss	32,416					32,416
Exercise of stock options and vesting of restricted stock units	12,100	$ 2	12,098
Exercise of stock options and vesting of restricted stock units, shares		1,331
Share-based compensation expense	15,700		15,700
Tax benefit related to equity compensation plans	1,346		1,346
Repurchases of common stock	(18,146)			$ (18,146)
Repurchases of common stock, shares				(547)
Balance at Jun. 30, 2014	1,821,881	$ 152	1,406,768	$ (2,197,890)	2,613,302	(451)
Balance, shares at Jun. 30, 2014		151,555		(71,251)
Balance at Dec. 31, 2014	1,709,222	$ 153	1,444,705	$ (2,341,652)	2,609,277	(3,261)
Balance, shares at Dec. 31, 2014		152,451		(74,378)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	88,356				88,356
Other comprehensive loss	(10,278)					(10,278)
Exercise of stock options and vesting of restricted stock units	18,224	$ 1	18,223
Exercise of stock options and vesting of restricted stock units, shares		1,277
Share-based compensation expense	13,735		13,735
Tax benefit related to equity compensation plans	5,028		5,028
Repurchases of common stock	(112,217)			$ (112,217)
Repurchases of common stock, shares				(2,064)
Balance at Jun. 30, 2015	$ 1,712,070	$ 154	$ 1,481,691	$ (2,453,869)	$ 2,697,633	$ (13,539)
Balance, shares at Jun. 30, 2015		153,728		(76,442)