U.S. Government Contracts and Grants - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues		$ 2,937,991	$ 643,978	$ 5,872,321	$ 5,225,600
Collaborative Arrangement [Member]
Revenues		$ 2,300,000		$ 2,300,000
Grant [Member] | Collaborative Arrangement [Member]
Revenues	$ 4,700,000