Quarterly Data (Unaudited) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Quarterly Data (Unaudited)
Net sales	$ 8,134	$ 7,752	$ 15,965	$ 15,386
Cost of sales	4,184	4,013	8,215	7,982
Net income including noncontrolling interest	1,283	1,213	2,508	2,360
Net income attributable to 3M	$ 1,267	$ 1,197	$ 2,474	$ 2,326
Earnings per share attributable to 3M common shareholders - basic (in dollars per share)	$ 1.94	$ 1.74	$ 3.77	$ 3.37
Earnings per share attributable to 3M common shareholders - diluted (in dollars per share)	$ 1.91	$ 1.71	$ 3.70	$ 3.32