Supplemental Equity and Comprehensive Income Information - AOCI Rollforward (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
AOCI Attributable to 3M, Net of Tax Roll Forward
Balance at the beginning of the period	$ 15,004	$ 13,828	$ 15,117	$ 12,931
Other comprehensive income (loss), before tax:
Total other comprehensive income (loss), net of tax	(532)	280	(617)	235
Balance at the end of the period	13,816	14,516	13,816	14,516
Total Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to 3M, Net of Tax Roll Forward
Balance at the beginning of the period	(6,834)	(7,767)	(6,750)	(7,721)
Other comprehensive income (loss), before tax:
Amounts before reclassifications	(536)	133	(680)	23
Amounts reclassified out	97	172	205	340
Total other comprehensive income (loss), before tax	(439)	305	(475)	363
Tax effect	(89)	(24)	(137)	(128)
Total other comprehensive income (loss), net of tax	(528)	281	(612)	235
Balance at the end of the period	(7,362)	(7,486)	(7,362)	(7,486)
Cumulative Translation Adjustment
AOCI Attributable to 3M, Net of Tax Roll Forward
Balance at the beginning of the period	(2,113)	(1,673)	(1,943)	(1,450)
Other comprehensive income (loss), before tax:
Amounts before reclassifications	(664)	159	(814)	(17)
Total other comprehensive income (loss), before tax	(664)	159	(814)	(17)
Tax effect	(37)	12	(57)	(35)
Total other comprehensive income (loss), net of tax	(701)	171	(871)	(52)
Balance at the end of the period	(2,814)	(1,502)	(2,814)	(1,502)
Defined Benefit Pension and Postretirement Plans Adjustment
AOCI Attributable to 3M, Net of Tax Roll Forward
Balance at the beginning of the period	(4,666)	(5,979)	(4,753)	(6,098)
Other comprehensive income (loss), before tax:
Amounts reclassified out	112	160	227	319
Total other comprehensive income (loss), before tax	112	160	227	319
Tax effect	(27)	(39)	(55)	(79)
Total other comprehensive income (loss), net of tax	85	121	172	240
Balance at the end of the period	(4,581)	(5,858)	(4,581)	(5,858)
Cash Flow Hedging Instruments, Unrealized Gain (Loss)
AOCI Attributable to 3M, Net of Tax Roll Forward
Balance at the beginning of the period	(55)	(115)	(54)	(173)
Other comprehensive income (loss), before tax:
Amounts before reclassifications	128	(26)	134	40
Amounts reclassified out	(15)	12	(22)	21
Total other comprehensive income (loss), before tax	113	(14)	112	61
Tax effect	(25)	3	(25)	(14)
Total other comprehensive income (loss), net of tax	88	(11)	87	47
Balance at the end of the period	$ 33	$ (126)	$ 33	$ (126)