Stock-Based Compensation - Schedule of Company's Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options Outstanding, Beginning balance	357,089	185,332
Stock Options Outstanding, Granted	159,500	195,500
Stock Options Outstanding, Exercised	(72,073)	(4,243)
Stock Options Outstanding, Cancelled or forfetied	(23,750)	(19,500)
Stock Options Outstanding, Ending balance	420,766	357,089	185,332
Stock Options Outstanding, Exercisable at December 31, 2019	109,390
Weighted-average Exercise Price, Beginning balance	$ 8.73	$ 3.91
Weighted-average Exercise Price, Granted	33.04	13.79
Weighted-average Exercise Price, Exercised	6.08	2.46
Weighted-average Exercise Price, Cancelled or forfeited	20.82	14.96
Weighted-average Exercise Price, Ending balance	17.71	$ 8.73	$ 3.91
Weighted-average Exercise Price, Exercisable at December 31, 2019	$ 7.52
Weighted-average Remaining Contractual Life (Years)	8 years 4 months 24 days	8 years 9 months 18 days	9 years
Weighted-average Remaining Contractual Life (Years), Exercisable	7 years 7 months 6 days
Aggregate intrinsic value, outstanding	$ 15,859	$ 4,302	$ 1,244
Aggregate Intrinsic Value, Exercisable	$ 5,236