Quarterly Data (Unaudited) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Quarterly Data (Unaudited)
Net sales	$ 7,831	$ 7,634
Cost of sales	4,031	3,969
Net income including noncontrolling interest	1,225	1,147
Net income attributable to 3M	$ 1,207	$ 1,129
Earnings per share attributable to 3M common shareholders - basic (in dollars per share)	$ 1.83	$ 1.63
Earnings per share attributable to 3M common shareholders - diluted (in dollars per share)	$ 1.79	$ 1.61