Pro Forma Consolidated Financial Information - Summary of Consolidated Results of Operations on Pro Forma Basis (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition Pro Forma Information [Abstract]
Pro forma revenue	$ 23,372,722	$ 6,494,483
Pro forma operating expenses	(29,392,193)	(10,419,169)
Pro forma net loss attributable to common stockholders	$ (13,865,962)	$ (6,722,174)