Consolidated Statement of Changes in Equity (Parenthetical) (USD $)	1 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Consolidated Statement of Changes in Equity
Dividends that have been declared but not yet paid (in dollars per share)	$ 1.025	$ 0.855

Dividends that have been declared in the current reporting period but are not paid until a subsequent reporting period and reside on the balance sheet until the date paid.

No definition available.

Name:	mmm_DividendsDeclaredInCurrentPeriodPaidInSubsequentPeriod
Namespace Prefix:	mmm_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration