CONDENSED 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, 2018	$ 1,048,231	$ 702	$ 632,235	$ 863,768	$ (355,857)	$ (92,617)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(25,963)			(25,963)
Other comprehensive income (loss)	1,321					1,321
Stock-based compensation	6,585		6,585
Shares issued and forfeited, net, under stock plans	5,665		(1,860)		7,525
Repurchase of common stock	(631)				(631)
Repurchase of stock-based compensation awards for tax withholdings	(2,624)				(2,624)
Ending balance at Mar. 31, 2019	1,032,584	702	636,960	837,805	(351,587)	(91,296)
Beginning balance at Dec. 31, 2019	1,129,968	702	667,658	930,830	(377,639)	(91,583)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(24,427)			(24,427)
Other comprehensive income (loss)	(6,169)					(6,169)
Stock-based compensation	6,950		6,950
Shares issued and forfeited, net, under stock plans	1,330		(17,885)		19,215
Repurchase of common stock	(28,881)				(28,881)
Repurchase of stock-based compensation awards for tax withholdings	(10,973)				(10,973)
Ending balance at Mar. 31, 2020	$ 1,067,798	$ 702	$ 656,723	$ 906,403	$ (398,278)	$ (97,752)