Commitments and Contingencies - Product Liability (Details)	12 Months Ended
Dec. 31, 2017 USD ($) individual lawsuit state case item	Dec. 31, 2016 lawsuit
Product Liability - Filters
Product Liability Litigation
Number of customers who obtained an order in the French Courts against 3M Purification SAS \| item	1
Number of cases settled in principle in period \| case	2
Product liability - Bair Hugger
Product Liability Litigation
Number of lawsuits filed \| lawsuit	4,270	1,260
Accrued loss contingency reserve \| $	$ 0
Number of federal bellwether cases with trial-ready dates set \| case	2
Number of total claims dismissed \| case	61
Product liability - Bair Hugger \| U.S. District Court for the Western District of Tennessee
Product Liability Litigation
Number of lawsuits filed \| lawsuit	1
Product Liability - Lava Ultimate Dental Restorative Material Member
Product Liability Litigation
Number of lawsuits pending \| lawsuit	1
Number of plaintiffs \| individual	29
Number of states involved in lawsuit \| state	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 federal bellwether cases that have a scheduled trial date set.

+ References

No definition available.

+ Details

Name:	mmm_NumberOfFederalBellwetherCases
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

Number of claims dismissed.

+ References

No definition available.

+ Details

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

- 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

Number of pending claims pertaining to a loss contingency.

+ References

+ Details

Name:	us-gaap_LossContingencyPendingClaimsNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- 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: