Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive (Loss) Income, Net	Accumulated Other Comprehensive (Loss) Income, Net Cumulative Effect, Period of Adoption, Adjustment	Accumulated Earnings	Accumulated Earnings Cumulative Effect, Period of Adoption, Adjustment	Treasury Stock
Beginning Balance at Dec. 31, 2017	$ 983,465		$ 82	$ 1,761,383	$ 1,508		$ 1,647,284		$ (2,426,792)
Beginning Balance (Accounting Standards Update 2018-02) at Dec. 31, 2017		$ 0				$ 591		$ (591)
Beginning Balance (Accounting Standards Update 2016-16) at Dec. 31, 2017		$ (13,717)						$ (13,717)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	122,456						122,456
Other comprehensive loss	(41,966)				(41,966)
Issuances under stock plans	10,181			(3,845)					14,026
Common share repurchases	(275,834)								(275,834)
Stock-based compensation expense	66,172			66,172
Ending Balance at Dec. 31, 2018	850,757		82	1,823,710	(39,867)		1,755,432		(2,688,600)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	233,290						233,290
Other comprehensive loss	(38,071)				(38,071)
Issuances under stock plans	17,649			6,555					11,094
Common share repurchases	(194,040)								(194,040)
Stock-based compensation expense	69,008			69,008
Ending Balance at Dec. 31, 2019	938,593		82	1,899,273	(77,938)		1,988,722		(2,871,546)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	266,745						266,745
Other comprehensive loss	(21,290)				(21,290)
Issuances under stock plans	18,143			7,117					11,026
Common share repurchases	(174,303)								(174,303)
Stock-based compensation expense	62,540			62,540
Ending Balance at Dec. 31, 2020	$ 1,090,428		$ 82	$ 1,968,930	$ (99,228)		$ 2,255,467		$ (3,034,823)