Cover Page - shares	6 Months Ended
	Jun. 29, 2025	Jul. 30, 2025
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 29, 2025
Document Transition Report	false
Entity File Number	1-3619
Entity Registrant Name	PFIZER INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-5315170
Entity Address, Address Line One	66 Hudson Boulevard East
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10001-2192
City Area Code	212
Local Phone Number	733-2323
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		5,685,550,500
Entity Central Index Key	0000078003
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	Q2
Amendment Flag	false
Common Stock, $.05 par value [Member]
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $0.05 par value
Trading Symbol	PFE
Security Exchange Name	NYSE
1.000% Notes due 2027 [Member]
Entity Information [Line Items]
Title of 12(b) Security	1.000% Notes due 2027
Trading Symbol	PFE/27
Security Exchange Name	NYSE
Notes Due 2029, 2.875% [Member]
Entity Information [Line Items]
Title of 12(b) Security	2.875% Notes due 2029
Trading Symbol	PFE/29
Security Exchange Name	NYSE
Notes Due 2032, 3.250% [Member]
Entity Information [Line Items]
Title of 12(b) Security	3.250% Notes due 2032
Trading Symbol	PFE/32
Security Exchange Name	NYSE
Notes Due 2037, 3.875% [Member]
Entity Information [Line Items]
Title of 12(b) Security	3.875% Notes due 2037
Trading Symbol	PFE/37A
Security Exchange Name	NYSE
Notes Due 2045, 4.250% [Member]
Entity Information [Line Items]
Title of 12(b) Security	4.250% Notes due 2045
Trading Symbol	PFE/45
Security Exchange Name	NYSE