Shareholders' Equity - Summary of Stock Option Activity (Detail)	3 Months Ended
	Mar. 31, 2016 USD ($) $ / shares shares
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward
Number of Shares, Beginning Balance | shares	1,778,697
Granted, Number of Shares | shares	168,775
Exercised, Number of Shares | shares	(19,081)
Forfeited, Number of Shares | shares	(15,843)
Expired, Number of Shares | shares	(390)
Number of Shares, Ending Balance | shares	1,912,158
Vested and expected to vest, Number of Shares, Ending Balance | shares	1,776,293
Exercisable, Number of Shares, Ending Balance | shares	838,549
Weighted Average Exercise Price, Beginning Balance | $ / shares	$ 4.43
Granted, Weighted Average Exercise Price | $ / shares	5.82
Exercised, Weighted Average Exercise Price | $ / shares	3.14
Forfeited, Weighted Average Exercise Price | $ / shares	5.79
Expired, Weighted Average Exercise Price | $ / shares	4.30
Weighted Average Exercise Price, Ending Balance | $ / shares	4.56
Vested and expected to vest, Weighted Average Exercise Price, Ending Balance | $ / shares	4.47
Exercisable, Weighted Average Exercise Price, Ending Balance | $ / shares	$ 3.62
Weighted Average Remaining Contractual Life (in years)	7 years 9 months 15 days
Vested and expected to vest, Weighted Average Remaining Contractual Life (in years)	7 years 8 months 5 days
Exercisable, Weighted Average Remaining Contractual Life (in years)	6 years 2 months 23 days
Aggregate Intrinsic Value | $	$ 2,918,097
Vested and expected to vest, Aggregate Intrinsic Value | $	2,845,908
Exercisable, Aggregate Intrinsic Value | $	$ 1,964,768