Consolidated Statement of Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Consolidated Statement of Income
Net sales	$ 32,136	$ 32,765	$ 31,657
Operating expenses
Cost of sales	17,136	16,682	16,055
Selling, general and administrative expenses	7,029	7,602	6,626
Research, development and related expenses	1,911	1,821	1,870
Gain on sale of businesses	(114)	(547)	(586)
Total operating expenses	25,962	25,558	23,965
Operating income	6,174	7,207	7,692
Interest expense and income
Other expense (income), net	462	207	144
Income before income taxes	5,712	7,000	7,548
Provision for income taxes	1,130	1,637	2,679
Net income including noncontrolling interest	4,582	5,363	4,869
Less: Net income attributable to noncontrolling interest	12	14	11
Net income attributable to 3M	$ 4,570	$ 5,349	$ 4,858
Weighted average 3M common shares outstanding - basic (in shares)	577.0	588.5	597.5
Earnings per share attributable to 3M common shareholders - basic (in dollars per share)	$ 7.92	$ 9.09	$ 8.13
Weighted average 3M common shares outstanding - diluted (in shares)	585.1	602.0	612.7
Earnings per share attributable to 3M common shareholders - diluted (in dollars per share)	$ 7.81	$ 8.89	$ 7.93