Quarterly Consolidated Financial Data (Unaudited) - Summary of Quarterly Consolidated Financial Data (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Total operating expenses	$ 27,744,236	$ 21,126,801	$ 17,778,834	$ 32,491,457	$ 24,428,170	$ 18,947,235	$ 13,448,219	$ 10,421,473	$ 99,141,328	$ 67,245,097	$ 32,846,577
Net loss	$ (29,164,647)	$ (22,924,815)	$ (18,326,992)	$ (32,484,146)	$ (24,806,984)	$ (19,135,612)	$ (13,762,214)	$ (10,640,376)	$ (102,900,600)	$ (68,345,186)	$ (30,965,464)
Net loss per common share, basic and diluted	$ (0.79)	$ (0.61)	$ (0.49)	$ (0.88)	$ (0.71)	$ (0.56)	$ (0.41)	$ (0.32)	$ (2.77)	$ (2.01)	$ (1.15)