Intangible Assets and Goodwill (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Indefinite-Lived Intangible Assets [Line Items]
Other indefinite-lived intangible assets	$ 400.0	$ 400.0
Goodwill	$ 1,002.2	$ 1,002.2
Semma Therapeutics, Inc.
Indefinite-Lived Intangible Assets [Line Items]
Other indefinite-lived intangible assets			$ 387.0
Goodwill			554.6
Exonics Therapeutics
Indefinite-Lived Intangible Assets [Line Items]
Other indefinite-lived intangible assets			13.0
Goodwill			$ 397.1