CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance at Dec. 31, 2013	$ 1,242,018	$ 407	$ 191,965	$ 1,069,816	$ (20,170)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Foreign currency translation adjustment	(30,034)				(30,034)
Net income	208,712			208,712
Comprehensive income	178,678
Options exercised and awards vested	2,849	1	2,848
Stock-based compensation	11,856		11,856
Excess tax benefits—stock options and awards	25		25
Repurchase of common stock	(190,234)	(20)	(190,214)
Ending Balance at Dec. 31, 2014	1,245,192	388	16,480	1,278,528	(50,204)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Foreign currency translation adjustment	(51,060)				(51,060)
Net income	192,008			192,008
Comprehensive income	140,948
Options exercised and awards vested	2,170		2,170
Stock-based compensation	13,125		13,125
Excess tax benefits—stock options and awards	(1,172)		(1,172)
Repurchase of common stock	(75,805)	(10)	(30,603)	(45,192)
Ending Balance at Dec. 31, 2015	1,324,458	378	0	1,425,344	(101,264)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Foreign currency translation adjustment	(49,141)				(49,141)
Net income	93,221			93,221
Comprehensive income	44,080
Options exercised and awards vested	2,206	1	2,205
Stock-based compensation	12,217		12,217
Excess tax benefits—stock options and awards	(2,241)		(2,241)
Repurchase of common stock	(24,234)	(4)	(6,713)	(17,517)
Other	(62)			(60)	(2)
Ending Balance at Dec. 31, 2016	$ 1,356,424	$ 375	$ 5,468	$ 1,500,988	$ (150,407)