Option Activity Under Plan (Detail) (Stock Options, USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Stock Options
Share Based Compensation Plans [Line Items]
Outstanding	3,432,188
Granted	50,000
Exercised	0
Forfeited/expired	0
Outstanding	3,482,188	3,432,188
Vested and expected to vest	3,482,188
Exercisable	181,771
Weighted - Average Exercise Price, Outstanding	$ 1.23
Weighted - Average Exercise Price, Granted	$ 0.37
Weighted - Average Exercise Price, Exercised	$ 0
Weighted - Average Exercise Price, Forfeited/expired	$ 0
Weighted - Average Exercise Price, Outstanding	$ 1.22	$ 1.23
Weighted - Average Exercise Price, Vested and expected to vest	$ 1.22
Weighted - Average Exercise Price, Exercisable	$ 0.32
Weighted Average Remaining Contractual Term (In years), Outstanding	5 years 9 months 18 days	6 years 9 months 18 days
Weighted Average Remaining Contractual Term (In years), Granted	9 years 6 months
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	7 years
Aggregate Intrinsic Value, Outstanding	$ 2,839
Aggregate Intrinsic Value, Outstanding	5,339	2,839
Aggregate Intrinsic Value, Vested and expected to vest	5,339
Aggregate Intrinsic Value, Exercisable	$ 4,130