Commitments and Contingencies - Product Liability (Details)	9 Months Ended	12 Months Ended
Sep. 30, 2019 USD ($) lawsuit item individual case	Dec. 31, 2018 item
Product Liability - Bair Hugger
Product Liability Litigation
Number of lawsuits filed	2
Number of plaintiffs \| item	2	5,015
Accrued loss contingency reserve \| $	$ 0
Number of total claims dismissed \| case	61
Product Liability - Bair Hugger and medical malpractice claims \| Hidalgo County Texas
Product Liability Litigation
Number of lawsuits filed	1
Product Liability - Bair Hugger and medical malpractice claims \| Missouri
Product Liability Litigation
Number of lawsuits filed	4
Number of cases petitioned to transfer jurisdictions	3
Product Liability - Dual-Ended Combat Arms Earplugs
Product Liability Litigation
Number of lawsuits filed	2,245
Number of putative class action and other lawsuits	13
Number of plaintiffs \| individual	11,297

This element represents the number of lawsuits that are petitioned to transfer jurisdictions.

No definition available.

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

- Definition

The number of putative class action and other lawsuits.

+ References

No definition available.

+ Details

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

- Definition

Amount of loss contingency liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349

+ Details

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

- Definition

Number of claims dismissed.

+ References

No definition available.

+ Details

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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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14435-108349

+ Details

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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

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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

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

- Details

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- Details

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- Details

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- Details

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- Details

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