Grant Revenue (Details) $ in Thousands	1 Months Ended			12 Months Ended
	Sep. 30, 2020 USD ($)	Apr. 30, 2020 USD ($)	Sep. 30, 2016 USD ($) contract_option	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Jul. 31, 2020 USD ($)
Disaggregation of Revenue [Line Items]
Number of contract options | contract_option			3
Revenues				$ 803,395	$ 60,209	$ 135,068
Deferred revenue				4,044,612	202,305
Grant revenue
Disaggregation of Revenue [Line Items]
Revenues				528,905	12,173	12,556
Deferred revenue				5,261	2,777
BARDA
Disaggregation of Revenue [Line Items]
Award amount		$ 483,300	$ 125,800
Other Commitment							$ 471,600
Amount committed for funding				444,300
Number of contract options exercised | contract_option			4
BARDA | Minimum
Disaggregation of Revenue [Line Items]
Award amount				483,300
BARDA | Maximum
Disaggregation of Revenue [Line Items]
Award amount				954,900
BARDA | Contract options
Disaggregation of Revenue [Line Items]
Available funding				8,400
Amount committed for funding				70,800
BARDA | Grant revenue
Disaggregation of Revenue [Line Items]
Revenues				521,652	7,608	6,736
DARPA
Disaggregation of Revenue [Line Items]
Award amount	$ 56,400
DARPA | Contract options
Disaggregation of Revenue [Line Items]
Available funding				51,400
Amount committed for funding				4,600
The Bill & Melinda Gates Foundation | Initial project
Disaggregation of Revenue [Line Items]
Available funding				11,400
Deferred revenue				80,000
Other Grant Revenue | Grant revenue
Disaggregation of Revenue [Line Items]
Revenues				$ 7,253	$ 4,565	$ 5,820