Stockholders' Equity - Schedule of Common Stock Shares Issued (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Equity [Abstract]
Shares issued for vested restricted stock units, Shares	56,500
Shares issued for Employee Stock Purchase Plan options, Shares	130,421
Sale of common stock and warrants, net of issuance costs, Shares		10,192,500
Note and accrued interest conversions, Shares		5,573,831
Common stock issued for services, Shares		20,408
Total common stock shares	186,921	15,786,739
Shares issued for Employee Stock Purchase Plan options, Value	$ 110,066
Sale of common stock and warrants, net of issuance costs, Value		$ 18,577,018
Note and accrued interest conversions, Value		11,130,261
Common stock issued for services, Value		50,000
Total common stock amount	$ 110,066	$ 29,757,279