Condensed Consolidated Statements Of Stockholders' Equity (USD $) In Thousands	Common Stock [Member]	Capital Surplus [Member]	Accumulated Other Comprehensive Income [Member]	Retained Earnings [Member]	Total
Balance at beginning of period, value at Dec. 31, 2009	$ 149	$ 854,081	$ 45,580
Balance at beginning of period, shares at Dec. 31, 2009	148,645
Net issuances of restricted stock, shares	1,417
Net issuances of restricted stock, value	1	(1)
Repurchases of common stock, shares	(3,210)
Repurchases of common stock, value	(3)	(55,674)		(27,511)
Cash dividends ($.42 per share and $.39 per share)		(44,074)		(13,768)
Stock-based compensation expense		43,213
Exercises of stock options, shares	282
Exercises of stock options, value		6,077
Translation adjustments			1,848		1,848
Tax impact of equity incentive plans		(859)
Net income				41,279	41,279
Balance at end of period, value at Sep. 30, 2010	147	802,763	47,428
Balance at end of period, shares at Sep. 30, 2010	147,134
Balance at beginning of period, value at Dec. 31, 2010	146	787,105	47,120		834,371
Balance at beginning of period, shares at Dec. 31, 2010	146,183
Net issuances of restricted stock, shares	1,252
Net issuances of restricted stock, value	1	(1)
Repurchases of common stock, shares	(5,238)
Repurchases of common stock, value	(5)	(33,088)		(107,298)
Cash dividends ($.42 per share and $.39 per share)		(61,016)
Stock-based compensation expense		38,193
Exercises of stock options, shares	661
Exercises of stock options, value	1	15,277
Translation adjustments			(3,597)		(3,597)
Tax impact of equity incentive plans		1,814
Net income				107,298	107,298
Balance at end of period, value at Sep. 30, 2011	$ 143	$ 748,284	$ 43,523		$ 791,950
Balance at end of period, shares at Sep. 30, 2011	142,858