Segment, Geographic and Other Revenue Information - Revenues by Products - Footnotes (Details) $ in Millions		3 Months Ended		9 Months Ended
		Oct. 01, 2023 USD ($)	Oct. 02, 2022 USD ($)	Oct. 01, 2023 USD ($)	Oct. 02, 2022 USD ($)
Revenue from External Customer [Line Items]
Revenues		$ 13,232	$ 22,638	$ 44,247	$ 76,040
Business Innovation Segment [Member]
Revenue from External Customer [Line Items]
Revenues	[1]	302	319	928	974
Business Innovation Segment [Member] | Pfizer CentreOne [Member]
Revenue from External Customer [Line Items]
Revenues	[2]	291	318	903	972
Biopharma [Member]
Revenue from External Customer [Line Items]
Revenues		12,930	22,319	43,320	75,066
Biopharma [Member] | Oncology [Member]
Revenue from External Customer [Line Items]
Revenues		$ 2,885	3,070	8,696	9,124
Biopharma [Member] | Bavencio alliance revenues [Member] | Oncology [Member]
Revenue from External Customer [Line Items]
Royalty on net sales, percentage		0.15
Revenues	[3]	$ 18	$ 73	186	198
BioNTech [Member] | Business Innovation Segment [Member] | Pfizer CentreOne [Member]
Revenue from External Customer [Line Items]
Revenues				$ 11	$ 108

[1] See Note 13A above for information about Business Innovation. Prior-period financial information has been revised to reflect the current period presentation.

[2] PC1 includes revenues from our contract manufacturing, including certain Comirnaty-related manufacturing activities performed on behalf of BioNTech ($11 million for the first nine months of 2023 and $108 million for the first nine months of 2022, respectively), and revenues from our active pharmaceutical ingredient sales operation, as well as revenues related to our manufacturing and supply agreements with former legacy Pfizer businesses/partnerships.

[3] In March 2023, it was announced that our alliance with Merck KGaA to co-develop and co-commercialize Bavencio (avelumab) would terminate. Effective June 30, 2023, Merck KGaA took full control of the global commercialization of Bavencio. Beginning in the third quarter of 2023, the related profit share was replaced by a 15% royalty to Pfizer on net sales of Bavencio, which is recorded in Other (income)/deductions––net. We and Merck KGaA will continue to operationalize our respective ongoing clinical trials for Bavencio; and Merck KGaA will control all future R&D activities.