Condensed Consolidated Statements Of Changes In Stockholders' Equity (USD $) In Thousands	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2008	$ 341	$ (252,380)	$ 502,787	$ 5,355	$ 116,206	$ 372,309
Balance, shares at Dec. 31, 2008	34,134	(6,136)
Net income					50,955	50,955
Foreign currency translation				3,432		3,432
Minimum pension liability adjustment, net of tax				99		99
Unrealized gain (loss) on derivatives, net of tax				19		19
Total comprehensive income						54,505
Issuance of common stock through employee benefit plans, value	6		3,145			3,151
Issuance of common stock through employee benefit plans, shares	606
Share-based compensation			14,938			14,938
Repurchase of equity component of convertible debt			(18)			(18)
Balance at Dec. 31, 2009	347	(252,380)	520,852	8,905	167,161	444,885
Balance, shares at Dec. 31, 2009	34,740	(6,136)
Net income					65,669	65,669
Foreign currency translation				(10,616)		(10,616)
Minimum pension liability adjustment, net of tax				89		89
Unrealized gain (loss) on derivatives, net of tax				(173)		(173)
Total comprehensive income						54,969
Issuance of common stock through employee benefit plans, value	8		10,610			10,618
Issuance of common stock through employee benefit plans, shares	787
Share-based compensation			20,769			20,769
Repurchase of common stock		(31,278)				(31,278)
Repurchase of common stock, shares		(858)
Balance at Dec. 31, 2010	355	(283,658)	552,231	(1,795)	232,830	499,963
Balance, shares at Dec. 31, 2010	35,527	(6,994)
Net income					27,989	27,989
Foreign currency translation				(5,624)		(5,624)
Minimum pension liability adjustment, net of tax				640		640
Unrealized gain (loss) on derivatives, net of tax				(2,314)		(2,314)
Total comprehensive income						20,691
Issuance of common stock through employee benefit plans, value	2		374			376
Issuance of common stock through employee benefit plans, shares	207
Share-based compensation			27,679			27,679
Purchase of option hedge on convertible notes			(42,895)			(42,895)
Equity portion of convertible notes issuance costs			(1,334)			(1,334)
Proceeds from equity component of convertible notes			43,170			43,170
Proceeds from the sale of stock purchase warrants			28,451			28,451
Repurchase of common stock		(83,463)				(83,463)
Repurchase of common stock, shares		(1,909)
Balance at Dec. 31, 2011	$ 357	$ (367,121)	$ 607,676	$ (9,093)	$ 260,819	$ 492,638
Balance, shares at Dec. 31, 2011	35,734	(8,903)