Stock-Based Compensation - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Number of Shares
Outstanding at December 31, 2015	979,334
Granted	1,365,230
Exercised	(101,816)
Forfeited	(212,231)
Outstanding at December 31, 2016	2,030,517	979,334
Vested and expected to vest at December 31, 2016	1,947,267
Options exercisable at December 31, 2016	518,521
Weighted Average Exercise Price
Outstanding at December 31, 2015	$ 5.38
Granted	8.32
Exercised	2.62
Forfeited	7.31
Outstanding at December 31, 2016	7.29	$ 5.38
Vested and expected to vest at December 31, 2016	7.50
Options exercisable at December 31, 2016	$ 5.21
Weighted Average Remaining Contractual Term, Outstanding	8 years 5 months 1 day	7 years 10 months 10 days
Weighted Average Remaining Contractual Term, Vested and expected to vest at December 31, 2016	8 years 7 months 6 days
Weighted Average Remaining Contractual Term, Options exercisable at December 31, 2016	7 years 2 months 5 days
Aggregate Intrinsic Value, Outstanding	$ 10,510	$ 9,141
Aggregate Intrinsic Value, Vested and expected to vest at December 31, 2016	9,688
Aggregate Intrinsic Value, Options exercisable at December 31, 2016	$ 3,757