Schedule of Stock Options Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Shares
Options exercised	(488,464)
Weighted Average Exercise Price
Options exercised		$ 0.17
Employee Stock Option [Member]
Shares
Beginning balance	1,141,040	0
Options assumed in the Merger (see Note 3)		1,141,040
Options granted	155,000	0
Options exercised	(639,800)	0
Options forfeited	(9,000)	0
Ending balance	647,240	1,141,040	0
Options exercisable	647,240
Weighted Average Exercise Price
Beginning balance	$ 3.95	$ 0
Options assumed in the Merger (see Note 3)		3.95
Options granted	9.85	0
Options exercised	4.11	0
Options forfeited	3.41	0
Ending balance	5.62	$ 3.95	$ 0
Options exercisable	$ 5.62
Weighted Average Remaining Contractual Term (Years)
Options outstanding	4 years 1 month 17 days	5 years 9 months 14 days
Options assumed in the Merger (see Note 3)		5 years 10 months 6 days
Options exercisable	4 years 1 month 17 days
Aggregate Intrinsic Value
Beginning Balance	$ 22,600,000	$ 0
Options assumed in the Merger (see Note 3)		22,600,000
Options exercised	9,800,000	0
Ending balance	9,200,000	$ 22,600,000	$ 0
Options exercisable	$ 9,200,000
Allied Pacific of California [Member]
Shares
Beginning balance	853,800	1,910,400
Options granted	0	0
Options exercised	0	(1,056,600)
Options forfeited	0	0
Ending balance	853,800	853,800	1,910,400
Options exercisable	853,800
Weighted Average Exercise Price
Beginning balance	$ 0.167	$ 0.167
Options granted	0	0
Options exercised	0	0.167
Options forfeited	0	0
Ending balance	0.167	$ 0.167	$ 0.167
Options exercisable	$ 0.167
Weighted Average Remaining Contractual Term (Years)
Options outstanding	9 months	1 year 9 months	2 years 9 months
Options exercisable	9 months
Aggregate Intrinsic Value
Beginning Balance	$ 508,864	$ 1,138,598
Options exercised	0	(629,734)
Ending balance	508,864	$ 508,864	$ 1,138,598
Options exercisable	$ 508,864