Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Mar. 22, 2021	Mar. 10, 2021	May 27, 2020
Subsequent Event [Line Items]
Net proceeds received			$ 48.9
Subsequent Event [Member] \| Over-Allotment Option [Member]
Subsequent Event [Line Items]
Sale of stock, number of shares issued in transaction	11,500,000
Sale of stock, price per share	$ 5.00
Net proceeds received	$ 53.7
Subsequent Event [Member] \| BARDA Contract [Member]
Subsequent Event [Line Items]
Total funding receives in future		$ 86.8
Contract period of performance		6 years
Subsequent Event [Member] \| Base Period BARDA Funding [Member] \| BARDA Contract [Member]
Subsequent Event [Line Items]
Total funding receives in future		$ 9.8
Subsequent Event [Member] \| Additional BARDA Funding [Member] \| BARDA Contract [Member]
Subsequent Event [Line Items]
Total funding receives in future		$ 77.0