Earnings Per Common Share Attributable to Pfizer Inc. Common Shareholders (Details) - USD ($) shares in Millions, $ in Millions		3 Months Ended
		Mar. 30, 2025	Mar. 31, 2024
EPS Numerator
Income from continuing operations attributable to Pfizer Inc. common shareholders		$ 2,967	$ 3,120
Discontinued operations––net of tax		0	(5)
Net income attributable to Pfizer Inc. common shareholders		2,967	3,115
EPS Numerator--Diluted
Income from continuing operations attributable to Pfizer Inc. common shareholders		2,967	3,120
Discontinued operations––net of tax		0	(5)
Net income attributable to Pfizer Inc. common shareholders		$ 2,967	$ 3,115
EPS Denominator
Weighted-average number of common shares outstanding––Basic (in shares)		5,675	5,657
Common-share equivalents (in shares)		36	40
Weighted-average number of common shares outstanding––Diluted (in shares)		5,710	5,697
Anti-dilutive common stock equivalents (in shares)	[1]	17	26

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