Name:	mmm_CashAndCashEquivalentsAbstract
Namespace Prefix:	mmm
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The cash and cash equivalents consisting of cash and temporary investments with maturities of three months or less when acquired.

+ Details

Name:	mmm_CashAndCashEquivalentsClassificationWhenAquiredMaturityPeriodMaximum
Namespace Prefix:	mmm
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The change in functional currency of this subsidiary (located in the highly inflationary country of Venezuela) and associated remeasurement beginning January 1, 2010 as a result of Venezuela's economic environment will decrease net sales of the Venezuelan subsidiary by approximately two-thirds in 2010 in comparison to 2009. Number in hundreths.

+ Details

Name:	mmm_ChangeInFunctionalCurrencyOfSubsidiaryInHighlyInflationaryCountryPercentAssociatedRemeasurement
Namespace Prefix:	mmm
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The cumulative inflation rate of a subsidiary (located in the highly inflationary country of Venezuela) as a percentage of the consolidated operating income. Number in hundredths.

+ Details

Name:	mmm_CumulativeInflationRateOfSubsidiaryInHighlyInflationaryCountryPercentRangeMinimum
Namespace Prefix:	mmm
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	mmm_EarningsPerShareDenominatorAbstract
Namespace Prefix:	mmm
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	mmm_EarningsPerShareNumeratorAbstract
Namespace Prefix:	mmm
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The threshold percentage for determining whether an economic environment is highly inflationary for purposes of determining the functional currency of an entity.

+ Details

Name:	mmm_HighlyInflationaryEconomicEnvironmentInflationThresholdPercent
Namespace Prefix:	mmm
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of years used in the calculation to determine whether an economic environment is highly inflationary for purposes of determining the functional currency of an entity.

+ Details

Name:	mmm_HighlyInflationaryEconomicEnvironmentNumberOfYearsUsedInCalculation
Namespace Prefix:	mmm
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Marketable securities intended to be held for longer than one year as of the balance sheet date.

+ Details

Name:	mmm_MarketableSecuritiesClassificationNoncurrentHoldingPeriodMinimum
Namespace Prefix:	mmm
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The operating income of a subsidiary (located in the highly inflationary country of Venezuela) as a percentage of the consolidated operating income. Number in hundredths.

+ Details

Name:	mmm_OperatingIncomeOfSubsidiaryInHighlyInflationaryCountryPercentOfConsolidatedAmount
Namespace Prefix:	mmm
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) in the future that were not included in the computation of diluted EPS because to do so would increase EPS amounts or decrease loss per share amounts for the period presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 13, 14

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 171

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 40
-Subparagraph c

+ Details

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix:	us-gaap
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of net income or loss for the period per each share of common stock outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph 21
-Article 9

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 36, 37, 38

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 20
-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph 18
-Article 7

+ Details

Name:	us-gaap_EarningsPerShareBasic
Namespace Prefix:	us-gaap
Data Type:	us-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of net income or loss for the period per each share of common stock and dilutive common stock equivalents outstanding during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 11, 12, 36

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 20
-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph 18
-Article 7

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph 21
-Article 9

+ Details

Name:	us-gaap_EarningsPerShareDiluted
Namespace Prefix:	us-gaap
Data Type:	us-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_EarningsPerShareReconciliationAbstract
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_ForeignCurrencyTranslationAbstract
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate awards of share options and nonvested shares to be issued to an employee under a share-based compensation arrangement are considered options for purposes of computing diluted earnings per share. Such share-based awards shall be considered to be outstanding as of the grant date for purposes of computing diluted earnings per share even though their exercise may be contingent upon vesting. Those share-based awards are included in the diluted Earnings Per Share (EPS) computation even if the employee may not receive (or be able to sell) the stock until some future date. Accordingly, all shares to be issued shall be included in computing diluted EPS if the effect is dilutive. The dilutive effect of share-based compensation arrangements shall be computed using the treasury stock method. If the equity share options or other equity instruments are outstanding for only part of a period, the shares issuable shall be weighted to reflect the portion of the period during which the equity instruments were outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 20

+ Details

Name:	us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
Namespace Prefix:	us-gaap
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_MarketableSecuritiesNoncurrentAbstract
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The portion of consolidated profit or loss for the period, net of income taxes, which is attributable to the parent. If the entity does not present consolidated financial statements, the amount of profit or loss for the period, net of income taxes.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 03
-Paragraph 19
-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph 38
-Subparagraph d

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph A7
-Appendix A

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 51
-Paragraph 38
-Subparagraph a

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph 20
-Article 9

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 130
-Paragraph 10, 15

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Emerging Issues Task Force (EITF)
-Number 87-21

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 28, 29, 30

+ Details

Name:	us-gaap_NetIncomeLoss
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The average number of shares issued and outstanding that are used in calculating diluted EPS, determined based on the timing of issuance of shares in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 40
-Subparagraph a

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 8

+ Details

Name:	us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
Namespace Prefix:	us-gaap
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of [basic] shares, after adjustment for contingently issuable shares and other shares not deemed outstanding, determined by relating the portion of time within a reporting period that common shares have been outstanding to the total time in that period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 171

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 40
-Subparagraph a

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 8

+ Details

Name:	us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Namespace Prefix:	us-gaap
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

Significant Accounting Policies (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009	Sep. 30, 2009	Jun. 30, 2009	Mar. 31, 2009	Dec. 31, 2010 years number	Dec. 31, 2009	Dec. 31, 2008
Foreign Currency Translation
Threshold percentage used to determine if economic environment is highly inflationary									100.00%
Number of years used to determine if economic environment is highly inflationary (in years)									3
Operating income of Venezuelan subsidiary as percent of consolidated amount high end of range									1.00%
Cumulative inflation rate of Venezuela in November 2009, low end of range									100.00%
Approximate net sales decrease of Venezuelan sub due to change in functional currency and remeasurment from January 1, 2010 in comparison to 2009									66.70%
Cash and cash equivalents
Cash and cash equivalents classification when aquired, maximum maturity period (in months)									3
Marketable securities.
Marketable securities classification, minimum holding period for classification as non-current (in years)									1
Earnings per share
Options outstanding not included in computation of diluted earnings per share (in shares)									26.3	54.3	41.0
Numerator:
Net income attributable to 3M (in dollars)	$ 928	$ 1,106	$ 1,121	$ 930	$ 935	$ 957	$ 783	$ 518	$ 4,085	$ 3,193	$ 3,460
Denominator:
Denominator for weighted average 3M common shares outstanding - basic (in shares)									713.7	700.5	699.2
Dilution associated with the Company's stock-based compensation plans (in shares)									11.8	6.2	8.0
Denominator for weighted average 3M common shares outstanding - diluted (in shares)									725.5	706.7	707.2
Earnings per share attributable to 3M common shareholders - basic (in dollars per share)	$ 1.30	$ 1.55	$ 1.57	$ 1.31	$ 1.32	$ 1.36	$ 1.12	$ 0.75	$ 5.72	$ 4.56	$ 4.95
Earnings per share attributable to 3M common shareholders - diluted (in dollars per share)	$ 1.28	$ 1.53	$ 1.54	$ 1.29	$ 1.30	$ 1.35	$ 1.12	$ 0.74	$ 5.63	$ 4.52	$ 4.89