Shareholders' Equity - Summary of Stock Option Activity (Detail) (USD $)	9 Months Ended
	Sep. 30, 2014
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward
Number of Shares, Beginning Balance	1,515,621
Granted, Number of Shares	740,458
Exercised, Number of Shares	(374,565)
Forfeited, Number of Shares	(96,531)
Expired, Number of Shares	(258,671)
Number of Shares, Ending Balance	1,526,312
Vested and expected to vest, Number of Shares, Ending Balance	1,407,188
Exercisable, Number of Shares, Ending Balance	593,423
Weighted Average Exercise Price, Beginning Balance	$ 3.36
Granted, Weighted Average Exercise Price	$ 3.48
Exercised, Weighted Average Exercise Price	$ 2.49
Forfeited, Weighted Average Exercise Price	$ 3.27
Expired, Weighted Average Exercise Price	$ 4.34
Weighted Average Exercise Price, Ending Balance	$ 3.48
Vested and expected to vest, Weighted Average Exercise Price, Ending Balance	$ 3.48
Exercisable, Weighted Average Exercise Price, Ending Balance	$ 3.50
Weighted Average Remaining Contractual Life (in years)	6 years 10 months 28 days
Vested and expected to vest, Weighted Average Remaining Contractual Life (in years)	6 years 8 months 23 days
Exercisable, Weighted Average Remaining Contractual Life (in years)	3 years 10 months 24 days
Aggregate Intrinsic Value	$ 954,646
Vested and expected to vest, Aggregate Intrinsic Value	900,866
Exercisable, Aggregate Intrinsic Value	$ 498,217