Stockholders' Equity - Additional Information 1 (Detail) - USD ($)							9 Months Ended
	Sep. 23, 2016	Aug. 04, 2015	May 08, 2015	May 01, 2015	Mar. 23, 2015	Feb. 28, 2014	Sep. 30, 2016	Dec. 31, 2015	Jul. 22, 2015	Apr. 04, 2013
Stockholders Equity [Line Items]
Unvested stock-based compensation at fair value of remaining shares							$ 892
Intrinsic value of options outstanding							$ 0
Exchange and Redemption Agreement with Sabby Healthcare Volatility Master Fund, Ltd. [Member]
Stockholders Equity [Line Items]
Additional warrants issue to warrant holders	4,823,736
Series A Convertible Preferred Stock [Member]
Stockholders Equity [Line Items]
Series A Convertible Preferred stock, shares outstanding							964	1,041
Series A Convertible Preferred Stock [Member] | Exchange and Redemption Agreement with Sabby Healthcare Volatility Master Fund, Ltd. [Member]
Stockholders Equity [Line Items]
Series A Convertible Preferred stock, shares outstanding	1,000						964		1,176
Effective conversion price per share	$ 0.18								$ 0.30	$ 0.64
Directors [Member] | Non-qualified Stock Options [Member]
Stockholders Equity [Line Items]
Options expiration term					7 years
Non-qualified stock options issued to directors					10,000
Options exercise price per share					$ 0.19
Stock options fair value per share					$ 0.14
2005 Equity Incentive Plan [Member]
Stockholders Equity [Line Items]
Common stock reserved for issuance							283,058
Plan expiration date							Oct. 20, 2015
Options expiration term							10 years
2005 Equity Incentive Plan [Member] | Directors, Officers and Chief Medical Advisor [Member]
Stockholders Equity [Line Items]
Common stock warrants, issued					1,125,000	1,457,100
Common stock warrants, term					10 years	10 years
Common stock warrants, exercise price					$ 0.60	$ 0.80
Common stock warrants, premium percentage					216.00%	57.00%
Common stock warrants, fair value per share					$ 0.10	$ 0.34
2005 Equity Incentive Plan [Member] | Directors and Employees [Member]
Stockholders Equity [Line Items]
Common stock warrants, issued				550,000
Common stock warrants, term				10 years
Common stock warrants, exercise price				$ 0.60
Common stock warrants, premium percentage				20.00%
Common stock warrants, fair value per share				$ 0.37
Common stock warrants, vested				300,000
Vesting period				1 year
2005 Equity Incentive Plan [Member] | Directors and Employees [Member] | One Year Anniversary of Grant Date [Member]
Stockholders Equity [Line Items]
Common stock warrants, vested				250,000
2005 Equity Incentive Plan [Member] | Consultant [Member]
Stockholders Equity [Line Items]
Common stock warrants, issued			100,000
Common stock warrants, term			10 years
Common stock warrants, exercise price			$ 0.60
Common stock warrants, premium percentage			33.00%
Common stock warrants, fair value per share			$ 0.41
Common stock warrants, vested			40,000
Agreement termination date							Aug. 04, 2015
Common stock warrants cancelled		60,000
2005 Equity Incentive Plan [Member] | Consultant [Member] | Warrants Vested Over Three Quarters [Member]
Stockholders Equity [Line Items]
Common stock warrants, vested			60,000