Consolidated Statement of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net sales	$ 7,634	$ 7,486
Operating expenses
Cost of sales	3,969	3,889
Selling, general and administrative expenses	1,589	1,552
Research, development and related expenses	430	411
Total operating expenses	5,988	5,852
Operating income	1,646	1,634
Interest expense and income
Interest expense	39	40
Interest income	(10)	(9)
Total interest expense - net	29	31
Income before income taxes	1,617	1,603
Tax effect	470	462
Net income including noncontrolling interest	1,147	1,141
Less: Net income attributable to noncontrolling interest	18	16
Net income attributable to 3M	$ 1,129	$ 1,125
Weighted average 3M common shares outstanding - basic (in shares)	691.1	696.8
Earnings per share attributable to 3M common shareholders - basic (in dollars per share)	$ 1.63	$ 1.61
Weighted average 3M common shares outstanding - diluted (in shares)	702.1	706.1
Earnings per share attributable to 3M common shareholders - diluted (in dollars per share)	$ 1.61	$ 1.59
Cash dividends paid per 3M common share (in dollars per share)	$ 0.635	$ 0.59