Stockholders' Equity - Additional Information (Detail) - USD ($)		9 Months Ended
	Dec. 11, 2020	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Stockholders Equity Note [Line Items]
Common stock, shares authorized			400,000,000	225,000,000
Cantor Fitzgerald & Co. and Stifel, Nicolaus & Company, Incorporated | Amendment No. 3 | Sales Agreements
Stockholders Equity Note [Line Items]
Maximum common stock offering price	$ 100,000,000.0
Percentage of proceeds payable as compensation to underwriter	2.00%
Issuance of common stock from public offerings, net of offering costs (in shares)		0