Business Segments (Details)	12 Months Ended
Dec. 31, 2012 Segment
Business Segments
Number of operating business segments	6
Number of operating business segments in next fiscal year	5

The number of reportable segments of the entity in the next fiscal year.

No definition available.

Name:	mmm_ReportingSegmentsNumberNextFiscalYear
Namespace Prefix:	mmm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration