Summary of Stock Option Activity (Detail) (USD $)	9 Months Ended
	Sep. 30, 2012
Number of Shares
Beginning Balance	546,001
Granted	8,000
Exercised	(3,334)
Forfeited	(117,667)
Ending Balance	433,000
Exercisable	425,000
Options vested and expected to vest thereafter	433,000
Weighted Average Exercise Price
Beginning Balance	$ 4.54
Granted	$ 1.80
Exercised	$ 0.90
Forfeited	$ 7.90
Ending Balance	$ 3.60
Exercisable	$ 3.64
Options vested and expected to vest thereafter	$ 3.60
Weighted-Average Remaining Contractual Term
Outstanding, beginning of period	0 years
Granted	0 years
Exercised	0 years
Forfeited	0 years
Outstanding, end of period	2 years 3 months 18 days
Exercisable	2 years 4 months 24 days
Options vested and expected to vest thereafter	2 years 3 months 18 days
Aggregate Intrinsic Value
Granted
Exercised
Forfeited
Outstanding, end of period	174,000
Exercisable	172,000
Options vested and expected to vest thereafter	$ 174,000