Acquisitions, Divestitures, Equity-Method Investments, Licensing Arrangements and Collaborative Arrangements - Schedule of Collaborative Arrangements and Non-collaborative Arrangement Transactions (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenues	[1]	$ 41,908	$ 41,172	$ 40,825
Cost of sales	[2]	(8,692)	(8,251)	(8,987)
Selling, informational and administrative expenses	[2]	(11,615)	(12,750)	(12,612)
Research and development expenses	[2]	(9,405)	(8,394)	(7,760)
Other income/(deductions)—net		(669)	(3,314)	(2,077)
Collaborative Arrangement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenues		5,703	4,953	4,107
Cost of sales	[3]	(61)	(52)	(34)
Selling, informational and administrative expenses	[4]	(194)	(176)	(92)
Research and development expenses	[5]	(192)	104	162
Other income/(deductions)—net	[6]	567	362	281
Product [Member] | Collaborative Arrangement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenues	[7]	284	305	268
Co-promotion [Member] | Collaborative Arrangement [Member]
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Revenues	[8]	$ 5,418	$ 4,648	$ 3,838

[1] On November 16, 2020, we completed the spin-off and the combination of our Upjohn Business with Mylan to form Viatris. On December 21, 2020, Pfizer and Viatris completed the termination of a pre-existing strategic collaboration between Pfizer and Mylan for generic drugs in Japan (Mylan-Japan) and we transferred the operations that were part of the Mylan-Japan collaboration to Viatris. Beginning in the fourth quarter of 2020, the financial results of the Upjohn Business and the Mylan-Japan collaboration are reported as Income from discontinued operations––net of tax for all periods presented. Prior-period financial information has been restated, as appropriate. Prior to the separation of the Upjohn Business, and beginning in 2020, Upjohn began managing our Meridian subsidiary, the manufacturer of EpiPen and other auto-injector products, and the Mylan-Japan collaboration. As a result, revenues associated with our Meridian subsidiary, except for product revenues for EpiPen sold in Canada, and Mylan-Japan were reported in Upjohn beginning in the first quarter of 2020. Beginning in the fourth quarter of 2020, the results of our Meridian subsidiary are reported in the Hospital therapeutic area for all periods presented in our consolidated financial statements.

[2] Exclusive of amortization of intangible assets, except as disclosed in Note 1L.

[3] Primarily relates to amounts paid to collaboration partners for their share of net sales or profits earned in collaboration arrangements where we are the principal in the transaction, and cost of sales for inventory purchased from our partners.

[4] Represents net reimbursements to our partners for selling, informational and administrative expenses incurred.

[5] Primarily relates to upfront payments and pre-approval milestone payments earned by our partners as well as net reimbursements.

[6] Primarily relates to royalties from our collaboration partners.

[7] Represents sales to our partners of products manufactured by us.

[8] Substantially all relates to amounts earned from our partners under co-promotion agreements. The increases in each of the periods presented reflect increases in alliance revenues from Eliquis and Xtandi.