Income (Loss) Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Numerator, in thousands:
Net-income used for calculation of basic EPS	$ 27,858	$ (24,096)	$ 15,516	$ (69,867)
Interest expense on convertible debt	1,289		3,774
Change in fair value of derivative liabilities	(760)		(2,115)
Loss on extinguishment of outstanding debt, as if converted	(8,496)		(10,497)
Total adjustments	(7,967)		(8,838)
Net income used for calculation of diluted EPS	$ 19,891		$ 6,678
Denominator:
Weighted average shares outstanding, basic	42,900,269	30,941,404	42,035,025	30,904,876
Effect of dilutive potential common shares:
Shares underlying Convertible Senior Secured Notes and interest make-whole	7,576,541		7,995,340
Warrants to purchase common stock	20,857		20,905
Stock options, stock appreciation rights, and non-vested stock options	327,966		326,916
Total potential dilutive common shares	7,925,364		8,343,161
Weighted average shares outstanding, diluted	50,825,633	30,941,404	50,378,186	30,904,876
Net income per share, basic	$ 0.65	$ (0.78)	$ 0.37	$ (2.26)
Net income per share, diluted	$ 0.39	$ (0.78)	$ 0.13	$ (2.26)
Convertible Notes Payable
Loss Per Share
Common stock equivalents excluded in the calculation of diluted loss per share		16,983,531		9,393,821
Warrant to Purchase Common Stock
Loss Per Share
Common stock equivalents excluded in the calculation of diluted loss per share		13,561		12,924
Stock options and Employee Stock Purchase Plan Awards
Loss Per Share
Common stock equivalents excluded in the calculation of diluted loss per share		166,531		159,808