Derivatives - BS Location (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Assets	$ 243	$ 296
Fair Value of Derivative Instruments, Liabilities	191	69
Derivatives designated as hedging instruments
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Assets	149	233
Fair Value of Derivative Instruments, Liabilities	94	18
Derivatives designated as hedging instruments \| Foreign currency forward/option contracts \| Other current assets
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Assets	56	148
Derivatives designated as hedging instruments \| Foreign currency forward/option contracts \| Other assets
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Assets	35	61
Derivatives designated as hedging instruments \| Foreign currency forward/option contracts \| Other current liabilities
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Liabilities	54	14
Derivatives designated as hedging instruments \| Foreign currency forward/option contracts \| Other liabilities
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Liabilities	35	3
Derivatives designated as hedging instruments \| Foreign currency forward/option contracts \| Current balance sheet location
Location and Fair Value Amount of Derivative Instruments
Derivative Notional Amount	2,371	2,815
Derivatives designated as hedging instruments \| Foreign currency forward/option contracts \| Noncurrent balance sheet location
Location and Fair Value Amount of Derivative Instruments
Derivative Notional Amount	1,187	1,240
Derivatives designated as hedging instruments \| Interest rate swap contracts
Location and Fair Value Amount of Derivative Instruments
Derivative Notional Amount	2,053	1,753
Derivatives designated as hedging instruments \| Interest rate swap contracts \| Other assets
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Assets	58	24
Derivatives designated as hedging instruments \| Interest rate swap contracts \| Other current liabilities
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Liabilities	5
Derivatives designated as hedging instruments \| Interest rate swap contracts \| Other liabilities
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Liabilities		1
Derivatives not designated as hedging instruments
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Assets	94	63
Fair Value of Derivative Instruments, Liabilities	97	51
Derivatives not designated as hedging instruments \| Foreign currency forward/option contracts
Location and Fair Value Amount of Derivative Instruments
Derivative Notional Amount	5,365	5,359
Derivatives not designated as hedging instruments \| Foreign currency forward/option contracts \| Other current assets
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Assets	94	63
Derivatives not designated as hedging instruments \| Foreign currency forward/option contracts \| Other current liabilities
Location and Fair Value Amount of Derivative Instruments
Fair Value of Derivative Instruments, Liabilities	$ 97	$ 51

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

+ Details

Name:	invest_DerivativeNotionalAmount
Namespace Prefix:	invest_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (a),(c)
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624163-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226000-175313

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4D
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=51814546&loc=SL51823488-111719

+ Details

Name:	us-gaap_DerivativeFairValueOfDerivativeAsset
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4D
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=51814546&loc=SL51823488-111719

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (a),(c)
-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624163-113959

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226000-175313

+ Details

Name:	us-gaap_DerivativeFairValueOfDerivativeLiability
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_DerivativesFairValueLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_DesignatedAsHedgingInstrumentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherCurrentAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherNoncurrentAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherCurrentLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherNoncurrentLiabilitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=mmm_CurrentBalanceSheetLocationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_BalanceSheetLocationAxis=mmm_NoncurrentBalanceSheetLocationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateSwapMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: