Document and Entity Information	6 Months Ended
	Jun. 30, 2017 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	Jun. 30, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	596,767,147
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2