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, shares at Dec. 31, 2012		148,727		67,426
Balance at Dec. 31, 2012	$ 1,557,030	$ 149	$ 1,329,000	$ (2,092,625)	$ 2,293,522	$ 26,984
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	170,126				170,126
Other comprehensive income (loss)	(59,851)					(59,851)
Exercise of stock options and vesting of restricted stock units, shares		1,497
Exercise of stock options and vesting of restricted stock units	20,071	$ 1	20,070
Share-based compensation expense	29,930		29,930
Tax (benefit) detriment related to equity compensation plans	(1,376)		(1,376)
Repurchases of common stock, shares				(3,278)
Repurchases of common stock	(87,119)			$ (87,119)
Balance, shares at Dec. 31, 2013		150,224		70,704
Balance at Dec. 31, 2013	1,628,811	$ 150	1,377,624	$ (2,179,744)	2,463,648	(32,867)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	145,629				145,629
Other comprehensive income (loss)	29,606					29,606
Exercise of stock options and vesting of restricted stock units, shares		2,227
Exercise of stock options and vesting of restricted stock units	37,654	$ 3	37,651
Share-based compensation expense	28,334		28,334
Tax (benefit) detriment related to equity compensation plans	1,096		1,096
Repurchases of common stock, shares				(3,674)
Repurchases of common stock	(161,908)			$ (161,908)
Balance, shares at Dec. 31, 2014		152,451		74,378
Balance at Dec. 31, 2014	1,709,222	$ 153	1,444,705	$ (2,341,652)	2,609,277	(3,261)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	185,677				185,677
Other comprehensive income (loss)	(1,390)					(1,390)
Exercise of stock options and vesting of restricted stock units, shares		1,325
Exercise of stock options and vesting of restricted stock units	18,716	$ 1	18,715
Share-based compensation expense	29,451		29,451
Tax (benefit) detriment related to equity compensation plans	4,691		4,691
Repurchases of common stock, shares				(2,080)
Repurchases of common stock	(113,287)			$ (113,287)
Balance, shares at Dec. 31, 2015		153,776		76,458
Balance at Dec. 31, 2015	$ 1,833,080	$ 154	$ 1,497,562	$ (2,454,939)	$ 2,794,954	$ (4,651)