Segment, Geographic and Other Revenue Information - Schedule of Segment Reporting Information by Segment - Footnotes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 30, 2025	Sep. 29, 2024	Mar. 31, 2024
Segment Reporting Information [Line Items]
Restructuring charges and certain acquisition-related costs	$ 678		$ 102
ViiV [Member]
Segment Reporting Information [Line Items]
Dividend income			(61)
Biopharma [Member] | ViiV [Member]
Segment Reporting Information [Line Items]
Dividend income	(39)
Paxlovid [Member]
Segment Reporting Information [Line Items]
Favorable adjustment for government emergency use authorization inventory returned to the company during the period	771	$ 771	771
Paxlovid [Member] | Biopharma [Member]
Segment Reporting Information [Line Items]
Favorable adjustment for government emergency use authorization inventory returned to the company during the period			$ 771
Reconciling Items [Member] | Certain Significant Items [Member]
Segment Reporting Information [Line Items]
Restructuring charges and certain acquisition-related costs	$ 666