Commitments and Contingencies - Product Liability (Details)	6 Months Ended	12 Months Ended
Jun. 30, 2017 USD ($) lawsuit case item	Dec. 31, 2016 item
Product Liability - Filters
Product Liability Litigation
Number of customers who obtained an order in the French Courts against 3M Purification SAS	1
Number of cases settled in principle in period	2
Product liability - Bair Hugger
Product Liability Litigation
Number of lawsuits filed	2,600	1,260
Accrued loss contingency reserve \| $	$ 0
Product liability - Bair Hugger \| U.S. District Court for the Western District of Tennessee
Product Liability Litigation
Number of lawsuits filed \| case	1
Product Liability Lava Ultimate Dental Restorative Material
Product Liability Litigation
Number of lawsuits filed \| lawsuit	2
Product Liability Lava Ultimate Dental Restorative Material \| U.S. District Court for the District of Minnesota
Product Liability Litigation
Number of lawsuits filed \| lawsuit	1
Number of plaintiffs	39
Number of states involved in lawsuit	13

Represents the number of customers who obtained an order in the French Courts against 3M Purification SAS.

No definition available.

Name:	mmm_LossContingencyCustomersWhoObtainedOrderInFrenchCourtsAgainst3MPurificationSASNumber
Namespace Prefix:	mmm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of cases resolved in the period.

+ References

No definition available.

+ Details

Name:	mmm_NumberOfCasedResolvedInPeriod
Namespace Prefix:	mmm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the number of states involved in a current lawsuit.

+ References

No definition available.

+ Details

Name:	mmm_NumberOfStatesInvolvedInLawsuit
Namespace Prefix:	mmm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of loss contingency liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14326-108349

+ Details

Name:	us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The total number of new claims filed pertaining to a loss contingency during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82911808&loc=d3e14435-108349

+ Details

Name:	us-gaap_LossContingencyNewClaimsFiledNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of plaintiffs that have filed claims pertaining to a loss contingency.

+ References

No definition available.

+ Details

Name:	us-gaap_LossContingencyNumberOfPlaintiffs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ProductLiabilityContingencyLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_ProductOrServiceAxis=mmm_ProductLiabilityFiltersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=mmm_ProductLiabilityBairHuggerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=mmm_UsDistrictCourtForWesternDistrictOfTennesseeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ProductOrServiceAxis=mmm_ProductLiabilityLavaUltimateDentalRestorativeMaterialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementGeographicalAxis=mmm_UsDistrictCourtForDistrictOfMinnesotaMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: