Consolidated Statements of Stockholders' Equity (USD $) In Thousands, unless otherwise specified	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, 2011	$ 1,443,146	$ 147	$ 1,278,037	$ (2,023,129)	$ 2,171,459	$ 16,632
Balance, shares at Dec. 31, 2011		146,804		64,847
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	122,063				122,063
Other comprehensive income (loss)	10,352					10,352
Exercise of stock options and vesting of restricted stock units, shares		1,923
Exercise of stock options and vesting of restricted stock units	16,942	2	16,940
Share-based compensation expense	28,893		28,893
Tax benefit (detriment) related to equity compensation plans	5,130		5,130
Repurchases of common stock, shares				(2,579)
Repurchases of common stock	(69,496)			(69,496)
Balance at Dec. 31, 2012	1,557,030	149	1,329,000	(2,092,625)	2,293,522	26,984
Balance, shares at Dec. 31, 2012		148,727		67,426
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 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	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 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