CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands	Total	COMMON STOCK:	CAPITAL SURPLUS:	ACCUMULATED OTHER COMPREHENSIVE INCOME:	RETAINED EARNINGS:
Balance at beginning of period at Dec. 31, 2011		$ 142	$ 759,476	$ 40,887
Balance at beginning of period, (in shares) at Dec. 31, 2011		142,086
Net issuances of restricted stock, (in shares)		1,264
Repurchases of common stock, (in shares)		(4,521)
Exercises of stock options, (in shares)		1,982
Net issuances of restricted stock		1	(1)
Net income	151,323				151,323
Foreign currency translation adjustments, net of tax	1,832			1,832
Repurchases of common stock		(4)	(7,715)		(121,388)
Cash dividends			(42,614)		(21,250)
Stock-based compensation expense			30,891
Exercise of stock options		2	37,840
Tax impact of equity incentive plans			6,450
Balance at end of period at Sep. 30, 2012		141	784,327	42,719	8,685
Balance at end of period, (in shares) at Sep. 30, 2012		140,811
Balance at beginning of period at Dec. 31, 2012	842,011	139	798,093	43,779
Balance at beginning of period, (in shares) at Dec. 31, 2012		139,439
Net issuances of restricted stock, (in shares)		959
Repurchases of common stock, (in shares)		(3,377)
Exercises of stock options, (in shares)		1,265
Net issuances of restricted stock		1	(1)
Net income	185,310				185,310
Foreign currency translation adjustments, net of tax	(4,486)			(4,486)
Repurchases of common stock		(3)			(118,957)
Cash dividends			(12,256)		(54,718)
Stock-based compensation expense			28,559
Exercise of stock options		1	29,895
Tax impact of equity incentive plans			3,428
Balance at end of period at Sep. 30, 2013	$ 898,784	$ 138	$ 847,718	$ 39,293	$ 11,635
Balance at end of period, (in shares) at Sep. 30, 2013		138,286