Consolidated Statements of Shareholders' Equity (USD $) In Thousands	Total	Common Stock [Member]	Additional Paid-In-Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Deferred Compensation Trust [Member]	Deferred Compensation Liability [Member]
Beginning Balance at Dec. 31, 2009	$ 1,757,262	$ 206	$ 830,531	$ 3,823,067	$ (2,896,542)	$ (40,799)	$ 40,799
Net income	206,005			206,005
Deferred compensation activity						13,217	(13,217)
Purchase of common stock for treasury	(417,079)				(417,079)
Equity-based compensation	53,136		53,136
Tax benefit from equity benefit plan activity	63,558		63,558
Proceeds from stock options exercised	77,492		77,492
Treasury stock issued upon option exercise and restricted share vesting			(73,483)		73,483
Ending Balance at Dec. 31, 2010	1,740,374	206	951,234	4,029,072	(3,240,138)	(27,582)	27,582
Net income	129,420			129,420
Deferred compensation activity						2,001	(2,001)
Purchase of common stock for treasury	(689,302)				(689,302)
Equity-based compensation	64,473		64,473
Tax benefit from equity benefit plan activity	22,835		22,835
Proceeds from stock options exercised	106,999		106,999
Treasury stock issued upon option exercise and restricted share vesting			(72,762)		72,762
Ending Balance at Dec. 31, 2011	1,374,799	206	1,072,779	4,158,492	(3,856,678)	(25,581)	25,581
Net income	180,588			180,588
Deferred compensation activity						250	(250)
Purchase of common stock for treasury	(227,281)				(227,281)
Equity-based compensation	64,841		64,841
Tax benefit from equity benefit plan activity	14,319		14,319
Proceeds from stock options exercised	73,211		73,211
Treasury stock issued upon option exercise and restricted share vesting			(55,451)		55,451
Ending Balance at Dec. 31, 2012	$ 1,480,477	$ 206	$ 1,169,699	$ 4,339,080	$ (4,028,508)	$ (25,331)	$ 25,331