Document and Entity Information - shares	6 Months Ended
	Jul. 01, 2018	Aug. 06, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	PFIZER INC
Entity Central Index Key	0000078003
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jul. 01, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q2
Amendment Flag	false
Trading Symbol	PFE
Entity Common Stock, Shares Outstanding		5,862,109,503