Stockholder's Equity (Details) (USD $)	0 Months Ended	9 Months Ended	12 Months Ended	1 Months Ended	9 Months Ended		0 Months Ended	12 Months Ended
	Apr. 08, 2009	Sep. 30, 2011	Dec. 31, 2010	Feb. 28, 2011 4.75% Convertible Senior Notes Due On 2018 [Member]	Sep. 30, 2011 4.75% Convertible Senior Notes Due On 2018 [Member]	Sep. 30, 2011 Common Stock [Member]	Apr. 08, 2009 Common Stock [Member]	Dec. 31, 2010 Warrants [Member]
Stockholder's Equity [Line Items]
Principal amount		$ 1,000		$ 230,000,000	$ 230,000,000
Convertible senior notes, maturity date		Feb. 01, 2018		Feb. 01, 2018	Feb. 01, 2018
Conversion feature of convertible notes		34,427,000		34,400,000
Deferred tax liability set-up related to the convertible notes (net of finance costs)		(23,924,000)
Issuance costs				1,900,000			2,000,000
Registered direct offering common stock, raised		500,000				1,000	31,000,000
Registered direct offering common stock yield for cash							29,000,000
Common stock, shares issued		71,473,000	70,259,000				5,927,343	2,227,963
Shares purchasable with issued warrants	5,038,237
Initial exercise price of warrants	$ 10.46
Fair value of warrant liabilities	12,600,000
Proceeds from warrant exercises								8,500,000
Warrant exercised to purchase common stock, shares			5,038,237					812,617
Warrants to purchase common stock on cashless settlement process								4,225,620
Common stock were exercised resulting in forfeiture								1,997,657
Warrants and rights outstanding			$ 0