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Acquisitions, Research Collaborations and Licensing Agreements - Narrative (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Jun. 30, 2025	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Business Acquisition [Line Items]
Research and development				$ 3,621.0	$ 3,992.0
Property, plant and equipment, net	$ 24,793.0			24,793.0		$ 23,779.0
HRS-5346 , Jiangsu Hengrui Pharmaceuticals Co., Ltd. | Forecast
Business Acquisition [Line Items]
Consideration transferred, asset acquisition			$ 200.0
Research and development			200.0
Jiangsu Hengrui Pharmaceuticals Co., Ltd. | Forecast
Business Acquisition [Line Items]
Future contingent developmental milestone payments (up to)			92.5
Future regulatory milestone payments (up to)			177.5
Maximum aggregate sales-based milestone payments			$ 1,500.0
WuXi Vaccines' facility
Business Acquisition [Line Items]
Consideration transferred, asset acquisition	437.0
WuXi Vaccines' facility | Asset under Construction
Business Acquisition [Line Items]
Property, plant and equipment, net	$ 759.0			$ 759.0
Harpoon Therapeutics, Inc.
Business Acquisition [Line Items]
Consideration transferred, asset acquisition		$ 765.0
Research and development					656.0
Asset acquisition, transaction costs		$ 56.0
Net assets acquired					$ 165.0

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