Earnings/(Loss) Per Common Share Attributable to Pfizer Inc. Common Shareholders (Details) - USD ($) shares in Millions, $ in Millions		3 Months Ended			9 Months Ended
		Sep. 29, 2024	Oct. 01, 2023		Sep. 29, 2024		Oct. 01, 2023
EPS/(LPS) Numerator
Income/(loss) from continuing operations attributable to Pfizer Inc. common shareholders		$ 4,473	$ (2,394)		$ 7,617		$ 5,477
Discontinued operations––net of tax		(8)	12		4		11
Net income/(loss) attributable to Pfizer Inc. common shareholders		4,465	(2,382)		7,621		5,488
EPS/(LPS) Numerator--Diluted
Income/(loss) from continuing operations attributable to Pfizer Inc. common shareholders and assumed conversions		4,473	(2,394)		7,617		5,477
Discontinued operations––net of tax		(8)	12		4		11
Net income attributable to Pfizer Inc. common shareholders and assumed conversions		$ 4,465	$ (2,382)		$ 7,621		$ 5,488
EPS/(LPS) Denominator
Weighted-average number of common shares outstanding––Basic (in shares)		5,667	5,646		5,663		5,642
Common-share equivalents (in shares)	[1]	39	0		36		72
Weighted-average number of common shares outstanding––Diluted (in shares)		5,705	5,646		5,699		5,714
Anti-dilutive common stock equivalents (in shares)		25	58	[2]	25	[2]	2	[2]

[1] For the three months ended October 1, 2023, due to the net loss attributable to Pfizer Inc. common shareholders, weighted average common-share equivalents of 56 million shares were not included in the computation of diluted LPS because their inclusion would have had an anti-dilutive effect.

[2] These common stock equivalents were outstanding for the periods presented, but were not included in the computation of diluted EPS/(LPS) for those periods because their inclusion would have had an anti-dilutive effect.