U.S. Government Agreements, Grants and Licenses - U.S. Department of Defense (Details) - U.S. Department of Defense - DoD Contract $ in Millions	1 Months Ended	3 Months Ended
	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)	Jun. 30, 2020 USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Initial funding	$ 60.0
Authorized expenditures or obligations	$ 22.0
Most-favored customer status period	5 years
Revenue recognized			$ 0.3
Forecast
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Doses of the vaccine candidate		10.0