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	1,410
Net issuances of restricted stock, value	1	(1)
Repurchases of common stock, shares	(2,726)
Repurchases of common stock, value	(2)	(55,674)		(16,085)
Cash dividends ($.28 per share and $.26 per share)		(34,114)		(4,571)
Stock-based compensation expense		29,124
Exercises of stock options, shares	247
Exercises of stock options, value		5,385
Translation adjustments			(14,676)		(14,676)
Tax impact of equity incentive plans		(1,032)
Net income				20,656	20,656
Balance at end of period, value at Jun. 30, 2010	148	797,769	30,904
Balance at end of period, shares at Jun. 30, 2010	147,576
Balance at beginning of period, value at Dec. 31, 2010	146	787,105	47,120		834,371
Balance at beginning of period, shares at Dec. 31, 2010	146,183
Net issuances of restricted stock, shares	1,265
Net issuances of restricted stock, value	1	(1)
Repurchases of common stock, shares	(3,151)
Repurchases of common stock, value	(3)	(28,412)		(63,130)
Cash dividends ($.28 per share and $.26 per share)		(40,976)
Stock-based compensation expense		25,447
Exercises of stock options, shares	584
Exercises of stock options, value	1	13,692
Translation adjustments			11,014		11,014
Tax impact of equity incentive plans		1,496
Net income				63,130	63,130
Balance at end of period, value at Jun. 30, 2011	$ 145	$ 758,351	$ 58,134		$ 816,630
Balance at end of period, shares at Jun. 30, 2011	144,881