Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive (Loss) Income, Net	Accumulated Earnings	Treasury Stock
Beginning Balance at Dec. 31, 2012	$ 306,673	$ 78	$ 679,871	$ 5,968	$ 908,482	$ (1,287,726)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	182,801				182,801
Other comprehensive income (loss)	2,377			2,377
Issuances under stock plans	6,034		(21,354)			27,388
Stock compensation tax benefits	25,392		25,392
Common share repurchases	(196,696)					(196,696)
Stock compensation expense			34,735
Ending Balance at Dec. 31, 2013	361,316	78	718,644	8,345	1,091,283	(1,457,034)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	183,766				183,766
Other comprehensive income (loss)	(29,515)			(29,515)
Issuances under stock plans	7,800		(11,727)			19,527
Stock compensation tax benefits	18,671		18,671
Common share repurchases	(419,712)					(419,712)
Stock compensation expense	38,845		38,845
Ending Balance at Dec. 31, 2014	161,171	78	764,433	(21,170)	1,275,049	(1,857,219)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	175,635				175,635
Other comprehensive income (loss)	(23,232)			(23,232)
Issuances under stock plans	7,531		(5,964)			13,495
Stock compensation tax benefits	13,928		13,928
Common share repurchases	(513,582)					(513,582)
Stock compensation expense	46,149		46,149
Ending Balance at Dec. 31, 2015	$ (132,400)	$ 78	$ 818,546	$ (44,402)	$ 1,450,684	$ (2,357,306)