Subsequent Event - Additional Information (Detail) (USD $)	1 Months Ended
	Feb. 11, 2013	Aug. 13, 2013 Subsequent Event Common Stock Offering	Jul. 01, 2013 Payment Of Accrued Interest To The Holders Of July 2012 Notes Subsequent Event
Subsequent Events [Line Items]
Common stock issued		12,000,000	123,231
Share issued, price per share	$ 3.00	$ 1.50
Gross proceeds from sale of common stock		$ 18,000,000
Net proceeds from shares sold		$ 16,200,000
Warrant exercise period		30 days
Warrants issued to purchase common stock		1,800,000