Common Stock Reserved for Issuance - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2020	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2020	Aug. 31, 2020
Class of Stock [Line Items]
Issuance of common stock		$ 1,140,000	$ 8,782,000
ATM Program [Member]
Class of Stock [Line Items]
Issuance of common stock, Shares	544,868	100,000		100,000
Issuance of common stock		$ 1,100,000		$ 1,100,000
ATM Program [Member] | Maximum [Member]
Class of Stock [Line Items]
Common stock reserved for issuance					$ 20,000,000