This element represents the adjustments for reductions in cost estimates.

No definition available.

Name:	mmm_AdjustmentForExitCostIncurred
Namespace Prefix:	mmm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents the costs incurred related to exit activities.

+ References

No definition available.

+ Details

Name:	mmm_ExitActivitiesCostIncurred
Namespace Prefix:	mmm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Discloses the amount charged against the accrued restructuring reserves, or earnings if not previously accrued, during the period for the specified type of restructuring cost.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b)(1))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(d))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

+ Details

Name:	us-gaap_RestructuringAndRelatedCostIncurredCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The number of positions eliminated during the period as a result of restructuring activities.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_RestructuringCostAndReserveAxis=us-gaap_EmployeeSeveranceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringPlanAxis=mmm_RestructuringActions2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_CostOfSalesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_SellingGeneralAndAdministrativeExpensesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=mmm_ResearchDevelopmentAndRelatedExpensesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RestructuringPlanAxis=mmm_RestructuringActions2017Member
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	srt_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	srt_ConsolidationItemsAxis=us-gaap_CorporateNonSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=mmm_IndustrialSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=mmm_SafetyAndGraphicsSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=mmm_HealthCareSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=mmm_ElectronicsAndEnergySegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=mmm_ConsumerSegmentMember
Namespace Prefix:
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Restructuring Actions and Exit Activities (Details) $ in Millions	3 Months Ended
	Dec. 31, 2018 USD ($)	Jun. 30, 2018 USD ($) individual	Dec. 31, 2017 USD ($)	Jun. 30, 2017 USD ($) item	Mar. 31, 2017 USD ($)
Employee-Related
Restructuring Cost and Reserve
Pre-tax charge related to exit activities			$ 23		$ 24
2018 Restructuring Actions
Restructuring Cost and Reserve
Restructuring and related cost, number of positions affected \| individual		1,200
Restructuring charges	$ 32	$ 105
Pre-tax charge related to exit activities	22
Adjustments for reductions in cost estimates	10
2018 Restructuring Actions \| Cost of sales
Restructuring Cost and Reserve
Restructuring charges	15	12
2018 Restructuring Actions \| Selling, general and administrative expenses
Restructuring Cost and Reserve
Restructuring charges	16	89
2018 Restructuring Actions \| Research, development and related expenses
Restructuring Cost and Reserve
Restructuring charges	$ 1	$ 4
2017 Restructuring Actions
Restructuring Cost and Reserve
Restructuring and related cost, number of positions affected \| item				1,300
Restructuring charges				$ 99
2017 Restructuring Actions \| Cost of sales
Restructuring Cost and Reserve
Restructuring charges				86
2017 Restructuring Actions \| Selling, general and administrative expenses
Restructuring Cost and Reserve
Restructuring charges				5
2017 Restructuring Actions \| Research, development and related expenses
Restructuring Cost and Reserve
Restructuring charges				8
Business Segments. \| 2017 Restructuring Actions \| Employee-Related
Restructuring Cost and Reserve
Restructuring charges				99
Corporate and Unallocated \| 2017 Restructuring Actions \| Employee-Related
Restructuring Cost and Reserve
Restructuring charges				6
Industrial \| Business Segments. \| 2017 Restructuring Actions \| Employee-Related
Restructuring Cost and Reserve
Restructuring charges				39
Safety And Graphics \| Business Segments. \| 2017 Restructuring Actions \| Employee-Related
Restructuring Cost and Reserve
Restructuring charges				9
Health Care \| Business Segments. \| 2017 Restructuring Actions \| Employee-Related
Restructuring Cost and Reserve
Restructuring charges				2
Electronics And Energy \| Business Segments. \| 2017 Restructuring Actions \| Employee-Related
Restructuring Cost and Reserve
Restructuring charges				7
Consumer \| Business Segments. \| 2017 Restructuring Actions \| Employee-Related
Restructuring Cost and Reserve
Restructuring charges				$ 36