Acquisitions (Asset Acquisitions) (Details) - USD ($) $ in Millions	1 Months Ended							12 Months Ended
	Dec. 31, 2023	Oct. 31, 2023	Aug. 31, 2023	Feb. 28, 2022	Dec. 31, 2021	Mar. 31, 2021	Jan. 31, 2021	Dec. 31, 2022
Business Acquisition [Line Items]
Acquired IPR&D Expense								$ 333.8
Mablink Biosciences SAS
Business Acquisition [Line Items]
Acquired IPR&D Expense	$ 256.6
Beam Therapeutics Inc.
Business Acquisition [Line Items]
Acquired IPR&D Expense		$ 216.3
DICE Therapeutics, Inc. (DICE)
Business Acquisition [Line Items]
Acquired IPR&D Expense			$ 1,915.5
Versanis Bio, Inc. (Versanis)
Business Acquisition [Line Items]
Acquired IPR&D Expense			604.1
Emergence Therapeutics AG
Business Acquisition [Line Items]
Acquired IPR&D Expense			$ 406.5
BioMarin Pharmaceutical Inc.
Business Acquisition [Line Items]
Acquired IPR&D Expense				$ 110.0
Foghorn Therapeutics Inc.
Business Acquisition [Line Items]
Acquired IPR&D Expense					$ 316.6
Rigel Pharmaceuticals, Inc.
Business Acquisition [Line Items]
Acquired IPR&D Expense						$ 125.0
Precision Biosciences, Inc.
Business Acquisition [Line Items]
Acquired IPR&D Expense							$ 107.8