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Acquisitions, Research Collaborations and Licensing Agreements - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions | 1 Months Ended | 3 Months Ended | 6 Months Ended |  |
--- | --- | --- | --- | --- | ---
Jul. 31, 2025 | Mar. 31, 2025 | Mar. 31, 2024 | Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2025 | Jun. 30, 2024 | May 31, 2025 | Dec. 31, 2024
Business Combination [Line Items] |  |  |  |  |  |  |  |  |
Research and development |  |  |  | $ 4,048.0 | $ 3,500.0 | $ 7,669.0 | $ 7,492.0 |  |
Property, plant and equipment, net |  |  |  | 25,236.0 |  | $ 25,236.0 |  |  | $ 23,779.0
Verona Pharma plc | Subsequent Event |  |  |  |  |  |  |  |  |
Business Combination [Line Items] |  |  |  |  |  |  |  |  |
Consideration transferred, asset acquisition (in dollars per depository share) | $ 107 |  |  |  |  |  |  |  |
Asset acquisition, share conversion, ordinary shares per depository shares (in shares) | 8 |  |  |  |  |  |  |  |
Consideration transferred, asset acquisition | $ 10,000.0 |  |  |  |  |  |  |  |
HRS-5346 , Jiangsu Hengrui Pharmaceuticals Co., Ltd. |  |  |  |  |  |  |  |  |
Business Combination [Line Items] |  |  |  |  |  |  |  |  |
Research and development |  |  |  | $ 200.0 |  |  |  |  |
Jiangsu Hengrui Pharmaceuticals Co., Ltd. |  |  |  |  |  |  |  |  |
Business Combination [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 Combination [Line Items] |  |  |  |  |  |  |  |  |
Consideration transferred, asset acquisition |  | $ 437.0 |  |  |  |  |  |  |
WuXi Vaccines' facility | Asset under Construction |  |  |  |  |  |  |  |  |
Business Combination [Line Items] |  |  |  |  |  |  |  |  |
Property, plant and equipment, net |  | $ 759.0 |  |  |  |  |  |  |
Harpoon Therapeutics, Inc. |  |  |  |  |  |  |  |  |
Business Combination [Line Items] |  |  |  |  |  |  |  |  |
Asset acquisition, transaction costs |  |  | $ 56.0 |  |  |  |  |  |
Consideration transferred, asset acquisition |  |  | $ 765.0 |  |  |  |  |  |
Research and development |  |  |  |  |  |  | 656.0 |  |
Net assets acquired |  |  |  |  |  |  | $ 165.0 |  |

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