Segment, Geographic and Other Revenue Information - Schedule of Segment Reporting Information by Segment - Footnotes (Details) - USD ($) $ in Millions |
1 Months Ended | 3 Months Ended | 9 Months Ended | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
May 31, 2026 |
Sep. 27, 2026 |
Sep. 28, 2025 |
Sep. 27, 2026 |
Sep. 28, 2025 |
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| Segment Reporting [Line Items] | |||||||||||
| Acquired in-process research and development expenses | $ 669 | $ 1,390 | $ 822 | $ 1,401 | |||||||
| Restructuring charges and certain acquisition-related costs | 893 | 1,600 | |||||||||
| Certain asset impairments | [1] | 0 | 260 | 4,325 | 577 | ||||||
| Certain legal matters, net | [2] | 13 | 191 | 1,047 | 755 | ||||||
| Net gain from the sale of investment in ViiV | [3] | 0 | 0 | 1,870 | 0 | ||||||
| Restructuring charges | 1,000 | ||||||||||
| 3SBio [Member] | In-Licensing Agreement Option [Member] | |||||||||||
| Segment Reporting [Line Items] | |||||||||||
| Acquired in-process research and development expenses | 1,350 | 1,350 | |||||||||
| Innovent [Member] | Collaborative Arrangement [Member] | |||||||||||
| Segment Reporting [Line Items] | |||||||||||
| Upfront payment to collaborators | $ 650 | 650 | 650 | ||||||||
| ViiV [Member] | |||||||||||
| Segment Reporting [Line Items] | |||||||||||
| Dividend income | (58) | (72) | (239) | (184) | |||||||
| Biopharma [Member] | |||||||||||
| Segment Reporting [Line Items] | |||||||||||
| Acquired in-process research and development expenses | 19 | 40 | 172 | 51 | |||||||
| Biopharma [Member] | ViiV [Member] | |||||||||||
| Segment Reporting [Line Items] | |||||||||||
| Dividend income | $ (58) | $ (72) | $ (239) | $ (184) | |||||||
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