Summary of Stock Option Activity (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Number of Shares
Beginning Balance	279,000	433,000
Granted	8,000	10,000
Exercised	(142,000)	(30,500)
Forfeited	(44,000)	(133,500)
Ending Balance	101,000	279,000
Exercisable	93,000
Options vested and expected to vest thereafter	101,000
Weighted Average Exercise Price
Beginning Balance	$ 3.31	$ 3.60
Granted	$ 3.30	$ 3.80
Exercised	$ 1.14	$ 0.94
Forfeited	$ 5.72	$ 4.84
Ending Balance	$ 5.31	$ 3.31
Exercisable	$ 5.48
Options vested and expected to vest thereafter	$ 5.31
Weighted-Average Remaining Contractual Term
Outstanding, end of period	4 years	2 years 6 months
Exercisable, end of period	3 years 6 months
Options vested and expected to vest thereafter	4 years
Aggregate Intrinsic Value
Outstanding, end of period	$ 15,300	$ 321,200
Exercisable	15,300
Options vested and expected to vest thereafter	$ 15,300