Shareholders' Equity - Summary of Stock Option Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward
Number of Shares, Beginning Balance	1,553,360	1,515,621
Granted, Number of Shares	564,450	848,208
Exercised, Number of Shares	(250,196)	(393,128)
Forfeited, Number of Shares	(81,666)	(122,280)
Expired, Number of Shares	(7,251)	(295,061)
Number of Shares, Ending Balance	1,778,697	1,553,360	1,515,621
Vested and expected to vest, Number of Shares, Ending Balance	1,656,034
Exercisable, Number of Shares, Ending Balance	762,555
Weighted Average Exercise Price, Beginning Balance	$ 3.50	$ 3.36
Granted, Weighted Average Exercise Price	6.37	3.53
Exercised, Weighted Average Exercise Price	3.18	2.50
Forfeited, Weighted Average Exercise Price	4.01	3.28
Expired, Weighted Average Exercise Price	2.82	4.34
Weighted Average Exercise Price, Ending Balance	4.43	$ 3.50	$ 3.36
Vested and expected to vest, Weighted Average Exercise Price, Ending Balance	4.35
Exercisable, Weighted Average Exercise Price, Ending Balance	$ 3.61
Weighted Average Remaining Contractual Life (in years)	7 years 9 months 29 days	7 years 15 days	3 years 11 months 5 days
Vested and expected to vest, Weighted Average Remaining Contractual Life (in years)	7 years 8 months 19 days
Exercisable, Weighted Average Remaining Contractual Life (in years)	6 years 3 months 11 days
Aggregate Intrinsic Value	$ 3,166,290
Vested and expected to vest, Aggregate Intrinsic Value	3,065,335
Exercisable, Aggregate Intrinsic Value	$ 1,911,371