Stock-Based Awards - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Shares, Beginning balance	920,731
Aggregate Intrinsic Value, Beginning balance		$ 1,297
Number of Shares, Granted	588,701
Number of Shares, Exercised	(18,524)
Number of Shares, Forfeited	(46,594)
Number of Shares, Ending balance	1,444,314	920,731
Number of Shares, Options exercisable	636,409	585,959
Number of Shares, Options vested and expected to vest	1,408,747	904,010
Weighted Average Exercise Price, Beginning balance	$ 4.36
Weighted Average Exercise Price, Granted	8.08
Weighted Average Exercise Price, Exercised	4.33
Weighted Average Exercise Price, Forfeited	5.14
Weighted Average Exercise Price, Ending balance	5.85	$ 4.36
Weighted Average Exercise Price, Options exercisable	4.00	3.78
Weighted Average Exercise Price, Options vested and expected to vest	$ 5.81	$ 4.37
Weighted-Average Remaining Contractual Term, Outstanding	7 years 8 months 12 days	6 years 4 months 24 days
Weighted Average Remaining Contractual Term, Options exercisable	5 years 9 months 18 days	5 years 2 months 12 days
Weighted Average Remaining Contractual Term, Options vested and expected to vest	7 years 7 months 6 days	6 years 3 months 19 days
Aggregate Intrinsic Value, Ending balance	$ 8,220
Aggregate Intrinsic Value, Options exercisable	4,550	$ 1,136
Aggregate Intrinsic Value, Options vested and expected to vest	$ 8,063	$ 1,289