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	86,803			86,803
Shares issued in connection with share-based compensation, shares		1,331
Shares issued in connection with share-based compensation	17,566		17,566
Payment of tax withholdings related to net share settlements	(11,682)		(11,682)
Share-based compensation	19,799		19,799
Shares repurchased and retired, shares		(1,272)
Shares repurchased and retired	$ (63,322)		(63,322)
Other comprehensive loss					(9,609)
Ending balance, shares at Jun. 30, 2018	80,944	80,944
Ending balance at Jun. 30, 2018	$ 1,024,239	$ 1	$ 186,816	$ 940,314	$ (102,892)