Option Activity Under Plan (Detail) (Stock Option, USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Stock Option
Share Based Compensation Plans [Line Items]
Outstanding	3,482,188
Granted	2,550,000
Exercised	0
Forfeited/expired	0
Outstanding	6,032,188	3,482,188
Vested and expected to vest	6,032,188
Exercisable	4,848,298
Weighted - Average Exercise Price, Outstanding	$ 1.22
Weighted - Average Exercise Price, Granted	$ 0.48
Weighted - Average Exercise Price, Exercised	$ 0
Weighted - Average Exercise Price, Forfeited/expired	$ 0
Weighted - Average Exercise Price, Outstanding	$ 0.90	$ 1.22
Weighted - Average Exercise Price, Vested and expected to vest	$ 1.22
Weighted - Average Exercise Price, Exercisable	$ 1.0535
Weighted Average Remaining Contractual Term (In years), Outstanding	6 years 9 months 18 days	5 years 9 months 18 days
Weighted Average Remaining Contractual Term (In years), Granted	9 years 7 months 6 days
Weighted Average Remaining Contractual Term (In years), Vested and expected to vest	5 years 9 months 18 days
Weighted Average Remaining Contractual Term (In years), Exercisable	6 years 2 months 12 days
Aggregate Intrinsic Value, Outstanding	$ 18,671,745
Aggregate Intrinsic Value, Vested and expected to vest	18,671,745
Aggregate Intrinsic Value, Exercisable	$ 14,824,475