Supplemental Equity and Comprehensive Income Information - AOCI Rollforward (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
AOCI Attributable to 3M, Net of Tax Roll Forward
Balance at the beginning of the period	$ 15,117	$ 12,931
Other comprehensive income (loss), before tax:
Total other comprehensive income (loss), net of tax	(85)	(45)
Balance at the end of the period	15,004	13,828
Total Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to 3M, Net of Tax Roll Forward
Balance at the beginning of the period	(6,750)	(7,721)
Other comprehensive income (loss), before tax:
Amounts before reclassifications	(144)	(110)
Amounts reclassified out	108	168
Total other comprehensive income (loss), before tax	(36)	58
Tax effect	(48)	(104)
Total other comprehensive income (loss), net of tax	(84)	(46)
Balance at the end of the period	(6,834)	(7,767)
Cumulative Translation Adjustment
AOCI Attributable to 3M, Net of Tax Roll Forward
Balance at the beginning of the period	(1,943)	(1,450)
Other comprehensive income (loss), before tax:
Amounts before reclassifications	(150)	(176)
Total other comprehensive income (loss), before tax	(150)	(176)
Tax effect	(20)	(47)
Total other comprehensive income (loss), net of tax	(170)	(223)
Balance at the end of the period	(2,113)	(1,673)
Defined Benefit Pension and Postretirement Plans Adjustment
AOCI Attributable to 3M, Net of Tax Roll Forward
Balance at the beginning of the period	(4,753)	(6,098)
Other comprehensive income (loss), before tax:
Amounts reclassified out	115	159
Total other comprehensive income (loss), before tax	115	159
Tax effect	(28)	(40)
Total other comprehensive income (loss), net of tax	87	119
Balance at the end of the period	(4,666)	(5,979)
Cash Flow Hedging Instruments, Unrealized Gain (Loss)
AOCI Attributable to 3M, Net of Tax Roll Forward
Balance at the beginning of the period	(54)	(173)
Other comprehensive income (loss), before tax:
Amounts before reclassifications	6	66
Amounts reclassified out	(7)	9
Total other comprehensive income (loss), before tax	(1)	75
Tax effect	0	(17)
Total other comprehensive income (loss), net of tax	(1)	58
Balance at the end of the period	$ (55)	$ (115)