Net Loss Per Share - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock excluded from the calculation of weighted average shares for diluted net loss per share	4,636
Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock excluded from the calculation of weighted average shares for diluted net loss per share	1,277,136
Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock excluded from the calculation of weighted average shares for diluted net loss per share	178,000	102,000
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Common stock excluded from the calculation of weighted average shares for diluted net loss per share	2,933,000	13,000