Brazil defined benefit plan curtailment gain.

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Namespace Prefix:	mmm
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of funding liability target required in 2008, PPA transition rules for defined benefit pension plans.

+ Details

Name:	mmm_DefinedBenefitPensionPlansPercentageOfFundingLiabilityTargetTransitionRulesBy2008
Namespace Prefix:	mmm
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of funding liability target required to be reached by 2010, PPA transition rules for defined benefit pension plans.

+ Details

Name:	mmm_DefinedBenefitPensionPlansPercentageOfFundingLiabilityTargetTransitionRulesBy2010
Namespace Prefix:	mmm
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the percentage of funding target for defined benefit pension plans, of the target liability.

+ Details

Name:	mmm_DefinedBenefitPensionPlansPercentageOfFundingTargetToTargetLiability
Namespace Prefix:	mmm
Data Type:	us-types:percentItemType
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Period Type:	instant

- Definition

The number of company-sponsored international plans aggregated together for disclosures purposes.

+ Details

Name:	mmm_DefinedBenefitPlanNumberOfPlans
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Period Type:	instant

- Definition

The number of company-sponsored worldwide plans aggregated together for disclosures purposes.

+ Details

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- Definition

The number of additional year of age for certain benefit calculations for enhanced pension benefits that are offered to and accepted by employees in connection with their termination of employment that are only offered for a short period of time.

+ Details

Name:	mmm_DefinedBenefitPlanSpecialTerminationBenefitsNumberOfAdditionalAgeOfPensionService
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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of additional years of pension service for enhanced pension benefits that are offered to and accepted by employees in connection with their termination of employment that are only offered for a short period of time.

+ Details

Name:	mmm_DefinedBenefitPlanSpecialTerminationBenefitsNumberOfAdditionalYearsOfPensionService
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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of participants who will receive special termination benefits that are offered to and accepted by employees in connection with their termination of employment that are only offered for a short period of time.

+ Details

Name:	mmm_DefinedBenefitPlanSpecialTerminationBenefitsNumberOfParticipants
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Data Type:	xbrli:pureItemType
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- Definition

The percentage of WG Trading Company holdings in relation to total fair value of the company's total plan assets.

+ Details

Name:	mmm_LimitedPartnershipInterestsWithWGTradingCompany
Namespace Prefix:	mmm
Data Type:	us-types:percentItemType
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Period Type:	instant

- Definition

Maximum percentage of medical inflation absorbed by the company in a year.

+ Details

Name:	mmm_MaximumPercentageMedicalInflationObsorbedByCompanyAYear
Namespace Prefix:	mmm
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represent the number of countries in which company has company-sponsored plans.

+ Details

Name:	mmm_NumberOfCountriesInWhichRetirementPlansSponsored
Namespace Prefix:	mmm
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Accrued benefit cost liability recorded on the balance sheet increase (decrease)

+ Details

Name:	mmm_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrentncreaseDecrease
Namespace Prefix:	mmm
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

If applicable, the cost of providing special or contractual termination benefits recognized during the period on the projected benefit obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph q

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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.

+ Details

Name:	us-gaap_DefinedBenefitPlanDisclosureLineItems
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- Definition

The amount of increase or decrease in the accumulated benefit obligation related to the effects of a change in the substantive terms of an existing defined benefit pension plan or the initiation of a new plan. A plan amendment may increase or decrease benefits, including those attributed to years of service already rendered.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 106
-Paragraph 518

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 87
-Paragraph 264

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph r

+ Details

Name:	us-gaap_DefinedBenefitPlanEffectOfPlanAmendmentOnAccumulatedBenefitObligation
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of increase or decrease in net periodic benefit cost related to the effects of a change in the substantive terms of an existing defined benefit plan or the initiation of a new plan. A plan amendment may increase or decrease benefits, including those attributed to years of service already rendered.

+ References

+ Details

Name:	us-gaap_DefinedBenefitPlanEffectOfPlanAmendmentOnNetPeriodicBenefitCost
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of increase or decrease in the fair value of plan assets during the reporting period.

+ Details

Name:	us-gaap_DefinedBenefitPlanFairValueOfPlanAssetsPeriodIncreaseDecrease
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of net (gain) loss recognized in net periodic benefit cost as a result of an irrevocable action that relieves the employer (or the plan) of primary responsibility for a benefit obligation and eliminates significant risks related to the obligation and the assets used to effect the settlement. Examples of transactions that constitute a settlement include (a) making lump-sum cash payments to plan participants in exchange for their rights to receive specified benefits and (b) purchasing nonparticipating annuity contracts to cover vested benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 88
-Paragraph 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 106
-Paragraph 518

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 87
-Paragraph 264

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 132R
-Paragraph 5
-Subparagraph h

+ Details

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Pension and Postretirement Benefit Plans (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		3 Months Ended		12 Months Ended		3 Months Ended
	Jun. 30, 2010	Dec. 31, 2010	Jun. 30, 2009 United States Qualified and Non-qualified Pension Benefits years	Dec. 31, 2010 United States Qualified and Non-qualified Pension Benefits	Dec. 31, 2009 International Qualified and Non-qualified Pension Benefits	Dec. 31, 2010 International Qualified and Non-qualified Pension Benefits	Mar. 31, 2008 Postretirement Benefits	Dec. 31, 2010 Postretirement Benefits	Dec. 31, 2009 Postretirement Benefits	Dec. 31, 2008 Postretirement Benefits
Benefit Plan Information
Company-sponsored retirement plans, minimum number of worldwide plans		60
Company-sponsored retirement plans, number of international plans						55
Company-sponsored retirement plans, number of countries		24				23
Percentage of funding target for defined benefit pension plans, of the target liability				100.00%
Percentage of funding liability target required by 2008				92.00%
Percentage of funding liability target required to be reached by 2011				100.00%
Accumulated postretirement benefit obligation increase (decrease)							$ (148)	$ 69	$ (168)
Accrued postretirement benefit cost recorded on balance increase (decrease)							(51)
Asset value of plan assets increase (decrease) from previous fiscal year							(97)
Defined benefit plan, effect of plan amendment on net periodic benefit cost - (increase)/decrease										15
Maximum percentage of medical inflation absorbed by the company (percent expressed as a decimal)								3.00%
Brazilian subsidiary defined benefit plan curtailment gain	22
Special termination benefits - number of additional years of pension service			1
Special termination benefits - number of additional years of age for certain benefit calculations			1
Special termination benefits - number of participants			700
Special termination benefits charge			21
Settlement charge incurred on lump sum payments to 3M Sumitomo (Japan) plan participants					$ 17
Percentage of WG Trading Company holdings in relation to total fair value of the company's total plan assets high end of range (percent expressed as a decimal)		1.00%