Condensed Consolidated Statement of Equity (Unaudited) (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive (Loss) Income [Member]
Beginning Balance at Dec. 31, 2013	$ 1,044,373	$ 1	$ 672,165	$ 425,796	$ (53,589)
Beginning Balance, Shares at Dec. 31, 2013	91,254	91,254
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Sse	58,538
Shares issued in connection with share-based compensation (shares)		1,020
Shares issued in connection with share-based compensation (value)	5,736		5,736
Tax withholdings related to net share settlements of restricted stock units	(15,247)		(15,247)
Share-based compensation	22,281		22,281
Shares repurchased and retired (shares)		(2,542)
Shares repurchased and retired (value)	(72,781)		(72,781)
Adjustment to redeemable noncontrolling interest to redemption value	25
Other comprehensive income	(6,305)				(6,305)
Ending Balance at Sep. 30, 2014	$ 1,036,620	$ 1	$ 612,154	$ 484,359	$ (59,894)
Ending Balance, Shares at Sep. 30, 2014	91,814	89,732