Significant Accounting Policies (Details) (USD $) In Millions, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Supplemental Balance Sheet Information
Revision of amounts previously presented related to purchase of additional shares of non-wholly owned consolidated subsidiaries, which increased cash used in financing activities and decreased cash used in investing activities			$ 33	$ 63
Earnings per share
Options outstanding not included in computation of diluted earnings per share (in shares)	3.7	30.7	3.6	30.5
Numerator:
Net income attributable to 3M	$ 1,160	$ 1,121	$ 2,241	$ 2,051
Denominator:
Denominator for weighted average 3M common shares outstanding - basic (in shares)	713.4	714.5	712.5	713.1
Dilution associated with the Company's stock-based compensation plans (in shares)	13.1	11.2	13.9	11.5
Denominator for weighted average 3M common shares outstanding - diluted (in shares)	726.5	725.7	726.4	724.6
Earnings per share attributable to 3M common shareholders - basic (in dollars per share)	$ 1.63	$ 1.57	$ 3.15	$ 2.88
Earnings per share attributable to 3M common shareholders - diluted (in dollars per share)	$ 1.60	$ 1.54	$ 3.09	$ 2.83