Condensed Consolidated Statement of Stockholder's Equity (Unaudited) - 9 months ended Sep. 30, 2017 - 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, 2016	84,368	84,368
Beginning balance at Dec. 31, 2016	$ 1,002,984	$ 1	$ 400,452	$ 724,949	$ (122,418)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	87,453			87,453
Shares issued in connection with share-based compensation (shares)		1,006
Shares issued in connection with share-based compensation (value)	6,330		6,330
Payments Related to Tax Withholding for Share-based Compensation	13,629
Tax withholdings related to net share settlements of restricted stock units	(13,629)
Share-based compensation	29,558		29,558
Shares repurchased and retired, shares		(3,000)
Shares repurchased and retired	(132,460)		(132,460)
Other comprehensive income	$ 25,901				25,901
Ending balance, shares at Sep. 30, 2017	84,303	82,374
Ending balance at Sep. 30, 2017	$ 1,006,137	$ 1	$ 290,251	$ 812,402	$ (96,517)