Earnings Per Common Share Attributable to Pfizer Inc. Common Shareholders (Details) - USD ($) shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Jul. 02, 2023	Jul. 03, 2022	Jul. 02, 2023	Jul. 03, 2022
EPS Numerator––Basic
Income from continuing operations attributable to Pfizer Inc. common shareholders		$ 2,329	$ 9,871	$ 7,871	$ 17,743
Discontinued operations––net of tax		(2)	34	(1)	26
Net income attributable to Pfizer Inc. common shareholders		2,327	9,906	7,870	17,769
EPS Numerator––Diluted
Income from continuing operations attributable to Pfizer Inc. common shareholders and assumed conversions		2,329	9,871	7,871	17,743
Discontinued operations––net of tax, attributable to Pfizer Inc. common shareholders and assumed conversions		(2)	34	(1)	26
Net income attributable to Pfizer Inc. common shareholders and assumed conversions		$ 2,327	$ 9,906	$ 7,870	$ 17,769
EPS Denominator
Weighted-average number of common shares outstanding––Basic		5,646	5,593	5,640	5,605
Common-share equivalents (in shares)		67	119	80	130
Weighted-average number of common shares outstanding––Diluted		5,713	5,712	5,720	5,735
Anti-dilutive common stock equivalents (in shares)	[1]	3	1	2	0

[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.