Stock Incentive Plan - Summary of Stock Option Activity (Detail)	9 Months Ended
	Sep. 30, 2019 USD ($) $ / shares shares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares Outstanding, Beginning Balance | shares	3,383,047
Number of Shares, Granted | shares	1,317,819
Number of Shares, Exercised | shares	(30,000)
Number of Shares, Forfeitures | shares	(131,587)
Number of Shares Outstanding, Ending Balance | shares	4,539,279
Number of Shares Exercisable, Ending Balance | shares	2,596,879
Weighted Average Exercise Price, Beginning Balance | $ / shares	$ 6.17
Weighted Average Exercise Price, Granted | $ / shares	7.86
Weighted Average Exercise Price, Exercised | $ / shares	5.00
Weighted Average Exercise Price, Forfeitures | $ / shares	7.28
Weighted Average Exercise Price, Ending Balance | $ / shares	6.64
Weighted Average Exercise Price Exercisable, Ending Balance | $ / shares	$ 5.80
Weighted Average Contractual Term, Outstanding	7 years 5 months 26 days
Weighted Average Contractual Term, Exercisable	6 years 5 months 1 day
Aggregate Intrinsic Value, Outstanding | $	$ 1,881,826	[1]
Aggregate Intrinsic Value, Exercisable | $	$ 1,834,416	[1]

[1] The aggregate intrinsic value in this table was calculated on the positive difference, if any, between the closing price per share of the Company’s common stock on September 30, 2019 of $5.27 and the price of the underlying options.