Consolidated Statement of Stockholders' Equity (Unaudited) (USD $) In Thousands, except Share data	Total	Common Stock	Additional Paid In Capital	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Retained Earnings
Beginning balance at Dec. 31, 2010	$ 593,270	$ 1,166	$ 765,326	$ (2,657)	$ (9)	$ (170,556)
Beginning balance, shares at Dec. 31, 2010		116,564,000
Comprehensive income:
Net income (loss)	174,902					174,902
Unrealized gains (losses) on investments	1				1
Tax benefit (provisions)
Comprehensive income	174,903
Issuance of common stock
Issuance of common stock, shares
Exercises of employee stock options	670	1	669
Exercises of employee stock options, shares		84,000
Vesting of restricted stock		1	(1)
Vesting of restricted stock, shares		144,000
Stock based compensation	4,926		4,926
Stock based compensation, shares		8,000
Repurchases of common stock	(731)			(731)
Ending balance at Sep. 30, 2011	$ 773,038	$ 1,168	$ 770,920	$ (3,388)	$ (8)	$ 4,346
Ending balance, shares at Sep. 30, 2011		116,800,000