Condensed Consolidated Statements of Stockholders' Equity Statement - USD ($) $ in Thousands	Total	Common Stock Shares [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]
Common stock, shares outstanding at Dec. 31, 2018		20,492,000
Stockholders' Equity Attributable to Parent at Dec. 31, 2018	$ 1,263,655		$ 2,049	$ 657,899	$ (95)	$ 620,747	$ (16,945)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period		254,000
Stock Issued During Period, Value, New Issues	$ 925		18		5,196
Adjustments to Additional Paid in Capital, Other				(4,289)
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation	(77,642)	(78,000)
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	$ (18,157)				(18,157)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	6,209			6,209
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(936)						(936)
Net Income (Loss) Attributable to Parent	30,998					30,998
Stockholders' Equity Attributable to Parent at Mar. 31, 2019	$ 1,282,694		2,067	659,819	(13,056)	651,745	(17,881)
Common stock, shares outstanding at Mar. 31, 2019		20,668,000
Common stock, shares outstanding at Dec. 31, 2019	20,742,000	20,742,000
Stockholders' Equity Attributable to Parent at Dec. 31, 2019	$ 1,377,244		2,074	668,947	(157)	721,782	(15,402)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period		155,000
Stock Issued During Period, Value, New Issues	$ 560		9		10,758
Adjustments to Additional Paid in Capital, Other				(10,207)
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation	(63,511)	(64,000)
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	$ (12,174)				(12,174)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	6,939			6,939
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax	(13,510)						(13,510)
Net Income (Loss) Attributable to Parent	16,834					16,834
Stockholders' Equity Attributable to Parent at Mar. 31, 2020	$ 1,375,893		$ 2,083	$ 665,679	$ (1,573)	$ 738,616	$ (28,912)
Common stock, shares outstanding at Mar. 31, 2020	20,825,000	20,833,000