CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss
Beginning balance at Dec. 31, 2016	$ 754,917	$ 702	$ 600,344	$ 545,731	$ (297,760)	$ (94,100)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	5,135			5,135
Other comprehensive income (loss)	16,744					16,744
Stock-based compensation	13,683		13,683
Shares issued and forfeited, net, under stock plans, including income tax benefits	16,816		(3,682)		20,498
Repurchase of common stock	(37,387)				(37,387)
Repurchase of stock-based compensation awards for tax withholdings	(5,311)				(5,311)
Ending balance at Dec. 31, 2017	764,597	702	610,345	550,866	(319,960)	(77,356)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	68,921			68,921
Other comprehensive income (loss)	(15,261)					(15,261)
Stock-based compensation	20,360		20,360
Shares issued and forfeited, net, under stock plans, including income tax benefits	22,748		1,530		21,218
Repurchase of common stock	(54,527)				(54,527)
Repurchase of stock-based compensation awards for tax withholdings	(2,588)				(2,588)
Cumulative effect of accounting change, ASC 606	243,981			243,981
Ending balance at Dec. 31, 2018	1,048,231	702	632,235	863,768	(355,857)	(92,617)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	67,062			67,062
Other comprehensive income (loss)	1,034					1,034
Stock-based compensation	36,763		36,763
Shares issued and forfeited, net, under stock plans, including income tax benefits	16,481		(1,340)		17,821
Repurchase of common stock	(35,617)				(35,617)
Repurchase of stock-based compensation awards for tax withholdings	(3,986)				(3,986)
Ending balance at Dec. 31, 2019	$ 1,129,968	$ 702	$ 667,658	$ 930,830	$ (377,639)	$ (91,583)