Supplemental Equity and Comprehensive Income Information - Reclassifications out of AOCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Amount Reclassified from Accumulated Other Comprehensive Income
Other expense (income), net	$ (50)	$ (33)	$ (88)	$ (82)
Total before tax	60	1,938	1,663	3,883
Tax effect	(23)	415	279	734
Net income	82	1,525	1,385	3,152
Cost of sales	5,093	4,719	9,919	9,244
Net income attributable to 3M	78	1,524	1,377	3,148
Reclassification out of Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Net income attributable to 3M	(73)	(130)	(155)	(256)
Defined benefit pension and postretirement plans adjustments | Reclassification out of Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Total before tax	(112)	(160)	(227)	(319)
Tax effect	27	39	55	79
Net income	(85)	(121)	(172)	(240)
Transition asset | Reclassification out of Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Other expense (income), net	(1)	(1)	(1)	(1)
Prior service benefit | Reclassification out of Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Other expense (income), net	15	15	28	30
Net actuarial loss | Reclassification out of Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Other expense (income), net	(125)	(173)	(252)	(346)
Curtailments/Settlements | Reclassification out of Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Other expense (income), net	(1)	(1)	(2)	(2)
Cash flow hedging instruments gains (losses) | Reclassification out of Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Other expense (income), net	(2)	(2)	(4)	(4)
Total before tax	15	(12)	22	(21)
Tax effect	(3)	3	(5)	5
Net income	12	(9)	17	(16)
Cost of sales	$ 17	$ (10)	$ 26	$ (17)