Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss, Net	Accumulated Earnings	Treasury Stock
Beginning 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	20,795				20,795
Other comprehensive loss	(21,699)			(21,699)
Issuances under stock plans	5,062		(2,911)			7,973
Common share repurchases	(29,837)					(29,837)
Stock-based compensation expense	31,819		31,819
Ending balance at Mar. 31, 2019	856,897	82	1,852,618	(61,566)	1,776,227	(2,710,464)
Beginning 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	75,097				75,097
Other comprehensive loss	(91,034)			(91,034)
Issuances under stock plans	5,654		(1,794)			7,448
Common share repurchases	(63,164)					(63,164)
Stock-based compensation expense	25,129		25,129
Ending balance at Mar. 31, 2020	$ 890,275	$ 82	$ 1,922,608	$ (168,972)	$ 2,063,819	$ (2,927,262)