Condensed Consolidated Statement of Stockholder's Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance, shares at Dec. 31, 2017		80,885
Beginning balance at Dec. 31, 2017	$ 1,007,876	$ 1	$ 224,455	$ 877,111	$ (93,691)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of new accounting standards	(23,192)			(23,600)	408
Net income	28,287			28,287
Shares issued in connection with share-based compensation, shares		1,151
Shares issued in connection with share-based compensation	15,473		15,473
Payment of tax withholdings related to net share settlements	(10,532)		(10,532)
Share-based compensation	8,677		8,677
Shares repurchased and retired, shares		(400)
Shares repurchased and retired	(18,479)		(18,479)
Other comprehensive loss	(101)				(101)
Ending balance, shares at Mar. 31, 2018		81,636
Ending balance at Mar. 31, 2018	$ 1,008,009	$ 1	219,594	881,798	(93,384)
Beginning balance, shares at Dec. 31, 2018	80,092	80,092
Beginning balance at Dec. 31, 2018	$ 1,000,498	$ 1	160,870	975,375	(135,748)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,687			1,687
Shares issued in connection with share-based compensation, shares		541
Shares issued in connection with share-based compensation	2,758		2,758
Payment of tax withholdings related to net share settlements	(8,551)		(8,551)
Share-based compensation	9,892		9,892
Other comprehensive loss	$ (7,013)				(7,013)
Ending balance, shares at Mar. 31, 2019	80,633	80,633
Ending balance at Mar. 31, 2019	$ 999,271	$ 1	$ 164,969	$ 977,062	$ (142,761)