Summary of the Status of the Options Granted (Detail) (2011 Equity Incentive Plan, USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
2011 Equity Incentive Plan
Shares
Beginning Balance	19,491,667	15,795,000
Granted	0	5,246,667
Cancelled	(4,416,667)	(1,550,000)
Exercised	0	0
Ending Balance	15,075,000	19,491,667	15,795,000
Number of shares exercisable	10,510,313	9,470,417
Weighted Average Exercise Price Per Share
Outstanding	$ 0.18	$ 0.20
Granted	$ 0	$ 0.12
Cancelled	$ 0.33	$ 0.18
Exercised	$ 0	$ 0
Outstanding	$ 0.14	$ 0.18	$ 0.20
Exercisable	$ 0.15	$ 0.24
Weighted Average Remaining Contractual Term (years)
Weighted-Average Remaining Contractual Term	6 years 11 months 8 days	8 years 2 months 12 days	8 years 2 months 12 days
Exercisable	6 years 5 months 12 days	6 years 8 months 16 days
Weighted Average Fair Value
Weighted average fair value of options granted during the period		$ 0.08