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)/Income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of new accounting standards	$ (23,192)			$ (23,600)	$ 408
Beginning balance, shares at Dec. 31, 2017	80,885	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]
Net income	109,254			109,254
Shares issued in connection with share-based compensation, shares		1,428
Shares issued in connection with share-based compensation	19,585		19,585
Payment of tax withholdings related to net share settlements	(12,623)		(12,623)
Share-based compensation	29,574		29,574
Shares repurchased and retired, shares		(1,751)
Shares repurchased and retired	$ (87,028)		(87,028)
Other comprehensive loss					(13,330)
Ending balance, shares at Sep. 30, 2018	80,562	80,562
Ending balance at Sep. 30, 2018	$ 1,030,116	$ 1	$ 173,963	$ 962,765	$ (106,613)