CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income [Member]	Retained Earnings [Member]
Stockholders' Equity at Dec. 31, 2009	$ 577,162	$ 153	$ 556,690	$ 736	$ 19,583
Shares, Outstanding at Dec. 31, 2009		153,279
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under plans		8,184
Issuance of common stock under plans (value)	45,310	8	45,302
Stock-based compensation	17,800		17,800
Excess tax benefit from share based compensation	3,166		3,166
Accumulated other comprehensive (loss) income	(256)			(256)
Net (loss) income	190,837				190,837
Stockholders' Equity at Dec. 31, 2010	834,019	161	622,958	480	210,420
Shares, Outstanding at Dec. 31, 2010		161,463
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under plans		4,662
Issuance of common stock under plans (value)	29,205	5	29,200
Stock-based compensation	25,786		25,786
Excess tax benefit from share based compensation	468		468
Accumulated other comprehensive (loss) income	(340)			(340)
Net (loss) income	48,150				48,150
Stockholders' Equity at Dec. 31, 2011	937,288	166	678,412	140	258,570
Shares, Outstanding at Dec. 31, 2011		166,125
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under plans		4,695
Issuance of common stock under plans (value)	18,404	5	18,399
Stock Repurchased and Retired During Period, Shares	(10,209)
Stock Repurchased and Retired During Period, Value	(50,000)	(10)	(49,990)
Stock-based compensation	29,255		29,255
Excess tax benefit from share based compensation	127		127
Accumulated other comprehensive (loss) income	(506)			(506)
Net (loss) income	(26,169)				(26,169)
Stockholders' Equity at Dec. 31, 2012	$ 908,399	$ 161	$ 676,203	$ (366)	$ 232,401
Shares, Outstanding at Dec. 31, 2012		160,611