Document and Entity Information	9 Months Ended
	Sep. 30, 2016 shares
Document and Entity Information [Abstract]
Entity Registrant Name	3M Company
Trading Symbol	mmm
Entity Central Index Key	0000066740
Document Type	10-Q
Document Period End Date	Sep. 30, 2016
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well Known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	601,466,401
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	Q3