Marketable Securities (Detail 2) (USD $) In Millions	Dec. 31, 2010
Marketable securities by contractual maturity
Due in one year or less	$ 794
Due after one year through three years	796
Due after three years through five years	17
Due after five years	34
Total marketable securities	$ 1,641

This item represents the fair value of debt securities which are expected to mature after five years from the balance sheet date which are categorized neither as held-to-maturity nor trading securities.

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- Definition

This item represents the fair value of debt securities which are expected to mature after one year and through three years from the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ Details

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Namespace Prefix:	mmm
Data Type:	xbrli:monetaryItemType
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- Definition

This item represents the fair value of debt securities which are expected to mature after three years and through five years from the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

This item represents the total of all debt securities grouped by maturity dates, at fair value, which are categorized neither as held-to-maturity nor trading securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 20

+ Details

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- Definition

This item represents the fair value of debt securities which are expected to mature within one year of the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 20
-Subparagraph a

+ Details

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