Summary of Significant Accounting Policies - Computation of Net Income (Loss) per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012		Sep. 30, 2013	Sep. 30, 2012
Net income (loss) per share-Basic:
Numerator for basic net (loss) income per share	$ (12,937)	$ 11,433	[1]	$ (24,981)	$ (1,663)	[1]
Denominator for basic net (loss) income per share	27,158,394	3,957,231	[1]	26,543,099	3,887,530	[1]
Basic net (loss) income per common share	$ (0.48)	$ 2.89	[1]	$ (0.94)	$ (0.43)	[1]
Net income (loss) per share-Diluted:
Numerator for diluted net income (loss) per share	(12,937)	11,433		(24,981)	(1,663)
Less: Fair value of stock warrants		(14,545)
Less: Fair value of derivatives		(1,894)
Net loss attributable to common share	$ (12,937)	$ (5,006)		$ (24,981)	$ (1,663)
Denominator for diluted net loss per share	27,158,394	3,957,231	[1]	26,543,099	3,887,530	[1]
Diluted net loss per common share	$ (0.48)	$ (1.27)	[1]	$ (0.94)	$ (0.43)	[1]

[1] Restated