Stockholders' Equity - Additional Information 2 (Detail) (USD $)	12 Months Ended		0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Jul. 10, 2006 Right	Dec. 31, 2014	Feb. 28, 2014
Stockholders Equity [Line Items]
Equity grants awarded	1,812,906	0
Unvested stock-based compensation at fair value of remaining shares	$ 360			360
Stock option compensation expense, recognized	508,628	40,750
Intrinsic value of options outstanding	0			0
Intrinsic value of options exercisable	0			0
Stockholder Rights Plan [Member]
Stockholders Equity [Line Items]
No of right for each share			1
Description Of Event For Occurrence Of Right	Acquisition of, 15% or more of the Company's common stock
Portion of newly created Series A Preferred Stock for each Right			0.001
Series A Junior Participating Preferred Stock , Exercise Price			$ 40.00
Expiration of plan	Jul. 10, 2016
Warrants [Member]
Stockholders Equity [Line Items]
Intrinsic value of options outstanding	0			0
Intrinsic value of options exercisable	$ 0			0
Series A Preferred Stock [Member] | Stockholder Rights Plan [Member]
Stockholders Equity [Line Items]
Redemption of right			0.001
2005 Equity Incentive Plan [Member]
Stockholders Equity [Line Items]
Common stock reserved for issuance	283,058			283,058
2005 Equity Incentive Plan [Member] | Directors, Officers and Chief Medical Advisor [Member]
Stockholders Equity [Line Items]
Common stock warrants, issued					1,457,100
Common stock warrants, term					10 years
Common stock warrants, exercise price					$ 0.80
Common stock warrants, premium percentage					57.00%
Common stock issued upon common stock warrants exercisable				1,810,906
2005 Equity Incentive Plan [Member] | Non Employees [Member]
Stockholders Equity [Line Items]
Common stock warrants, issued				50,000