Income Taxes - Components of Net Loss Before Income Tax Benefit (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
U.S. operations	$ 18,562,738	$ 38,979,638
Non-U.S. operations	2,015,893	6,341,308
Net loss before income tax benefit	$ 20,578,631	$ 45,320,946