Loss Per Share - Weighted Average Share (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Unvested restricted stock	34,929	14,945	38,431	9,065
Total common stock equivalents	60,553	42,035	91,251	56,517
Common Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock	25,313	18,785	51,992	21,281
Common Stock Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock	311	8,305	828	26,171