Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income including noncontrolling interest	$ 1,437	$ 1,434	$ 4,589	$ 4,047
Other comprehensive income (loss), net of tax:
Cumulative translation adjustment	(302)	271	(354)	(67)
Defined benefit pension and postretirement plans adjustment	119	116	359	271
Cash flow hedging instruments	48	(71)	95	(60)
Total other comprehensive income (loss), net of tax	(135)	316	100	144
Comprehensive income (loss) including noncontrolling interest	1,302	1,750	4,689	4,191
Comprehensive (income) loss attributable to noncontrolling interest	(2)	(5)	(6)	(1)
Comprehensive income (loss) attributable to 3M	$ 1,300	$ 1,745	$ 4,683	$ 4,190