Summary of Significant Accounting Policies - Summary of Effect of Revision on Line Items Within Statement of Operations (Detail) - USD ($)	3 Months Ended			6 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2019	Jun. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Summary Of Significant Accounting Policies [Line Items]
Net loss attributable to common stockholders			$ (3,395,697)	$ (5,961,024)		$ (8,749,142)	$ (11,510,646)
Basic and diluted	$ (0.70)	$ (4.87)	$ (6.82)	$ (11.15)	$ (3.63)	$ (15.99)	$ (20.79)
Previously Reported [Member]
Summary Of Significant Accounting Policies [Line Items]
Net loss attributable to common stockholders			$ (2,598,060)	$ (5,163,387)		$ (7,951,505)	$ (10,713,009)
Basic and diluted			$ (5.22)	$ (9.66)		$ (14.53)	$ (19.35)
Adjustments [Member]
Summary Of Significant Accounting Policies [Line Items]
Net loss attributable to common stockholders			$ (797,637)	$ (797,637)		$ (797,637)	$ (797,637)
Basic and diluted			$ (1.60)	$ (1.49)		$ (1.46)	$ (1.44)