Supplemental Equity and Comprehensive Income Information - Reclassifications out of AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Amount Reclassified from Accumulated Other Comprehensive Income
Other expense (income), net	$ (38)	$ (49)
Total before tax	1,603	1,945
Tax effect	302	319
Net income	1,303	1,627
Cost of sales	4,826	4,525
Net income attributable to 3M	1,299	1,624
Reclassification out of Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Net income attributable to 3M	(82)	(126)
Defined benefit pension and postretirement plans adjustments | Reclassification out of Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Total before tax	(115)	(159)
Tax effect	28	40
Net income	(87)	(119)
Transition asset | Reclassification out of Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Other expense (income), net	0	0
Prior service benefit | Reclassification out of Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Other expense (income), net	13	15
Net actuarial loss | Reclassification out of Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Other expense (income), net	(127)	(173)
Curtailments/Settlements | Reclassification out of Accumulated Other Comprehensive Income
Amount Reclassified from Accumulated Other Comprehensive Income
Other expense (income), net	(1)	(1)
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)
Total before tax	7	(9)
Tax effect	(2)	2
Net income	5	(7)
Cost of sales	$ 9	$ (7)