Inventories - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Inventory [Line Items]
Inventory reserves	$ 510.0	$ 510.0	$ 136.4
Inventory write-downs and reserves		$ 457.1	$ 39.2	$ 73.8
REGEN-COV
Inventory [Line Items]
Inventory write-downs and reserves	$ 231.7