Stockholders' Equity - Equity Financings - Additional Information (Detail) - USD ($)	1 Months Ended			3 Months Ended		9 Months Ended
	Aug. 31, 2021	Feb. 28, 2021	Feb. 29, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Jun. 23, 2020	Jun. 22, 2020
Class Of Stock [Line Items]
Common stock, shares authorized				300,000,000		300,000,000		300,000,000	300,000,000
Equity Financings [Member]
Class Of Stock [Line Items]
Common stock, shares authorized										150,000,000
Equity Financings [Member] | Share Offering [Member]
Class Of Stock [Line Items]
Common stock issued		10,465,000	1,500,000
Price per share		$ 11.00	$ 14.50
Common stock, additional shares issued		1,365,000
Gross proceeds from issuance of common stock		$ 115,100,000	$ 21,750,000
Share issuance costs		$ 7,200,000	$ 1,800,000
At-the-Market Offering [Member]
Class Of Stock [Line Items]
Common stock issued				0	602,945	48,538	602,945
Price per share				$ 11.37	$ 8.12	$ 11.37	$ 8.12
Gross proceeds from issuance of common stock						$ 552,000	$ 4,900,000
Share issuance costs						$ 53,000	$ 250,000
Stock issuances, sales agent commission maximum percentage	3.00%