Condensed Consolidated Statement of Stockholder's Equity (Unaudited) - 6 months ended Jun. 30, 2016 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
Beginning Balance, Shares at Dec. 31, 2015	88,228	88,228
Beginning Balance at Dec. 31, 2015	$ 1,049,490	$ 1	$ 551,206	$ 618,399	$ (120,116)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	67,902			67,902
Shares issued in connection with share-based compensation (shares)		865
Shares issued in connection with share-based compensation (value)	9,801		9,801
Tax withholdings related to net share settlements of restricted stock units	(9,098)		(9,098)
Share-based compensation	19,318		19,318
Shares repurchased and retired, shares		(800)
Shares repurchased and retired	(29,126)		(29,126)
Other comprehensive income	$ 1,972				1,972
Ending Balance, Shares at Jun. 30, 2016	88,293	88,293
Ending Balance at Jun. 30, 2016	$ 1,110,259	$ 1	$ 542,101	$ 686,301	$ (118,144)