Supplemental Equity and Comprehensive Income Information - AOCI rf (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
AOCI Attributable to 3M, Net of Tax [Roll Forward]
Stockholders' Equity Attributable to 3M, Beginning Balance			$ 10,298
Other comprehensive income (loss), before tax:
Stockholders' Equity Attributable to 3M, Ending Balance	$ 11,591		11,591
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to 3M, Net of Tax [Roll Forward]
Stockholders' Equity Attributable to 3M, Beginning Balance	(6,949)	$ (6,261)	(7,245)	$ (6,359)
Other comprehensive income (loss), before tax:
Amounts before reclassifications	(241)	44	(116)	(17)
Amounts reclassified out	114	73	215	124
Total other comprehensive income (loss), before tax	(127)	117	99	107
Tax effect	87	(40)	157	68
Total other comprehensive income (loss), net of tax	(40)	77	256	175
Stockholders' Equity Attributable to 3M, Ending Balance	(6,989)	(6,184)	(6,989)	(6,184)
Cumulative Translation Adjustment
AOCI Attributable to 3M, Net of Tax [Roll Forward]
Stockholders' Equity Attributable to 3M, Beginning Balance	(1,719)	(1,540)	(2,008)	(1,679)
Other comprehensive income (loss), before tax:
Amounts before reclassifications	(167)	59	59	119
Total other comprehensive income (loss), before tax	(167)	59	59	119
Tax effect	100	(22)	163	57
Total other comprehensive income (loss), net of tax	(67)	37	222	176
Stockholders' Equity Attributable to 3M, Ending Balance	(1,786)	(1,503)	(1,786)	(1,503)
Gains (losses) associated with defined benefit pension and postretirement plans amortization
AOCI Attributable to 3M, Net of Tax [Roll Forward]
Stockholders' Equity Attributable to 3M, Beginning Balance	(5,245)	(4,735)	(5,328)	(4,804)
Other comprehensive income (loss), before tax:
Amounts reclassified out	119	101	238	204
Total other comprehensive income (loss), before tax	119	101	238	204
Tax effect	(41)	(34)	(77)	(68)
Total other comprehensive income (loss), net of tax	78	67	161	136
Stockholders' Equity Attributable to 3M, Ending Balance	(5,167)	(4,668)	(5,167)	(4,668)
Cash flow hedging instruments gains (losses)
AOCI Attributable to 3M, Net of Tax [Roll Forward]
Stockholders' Equity Attributable to 3M, Beginning Balance	15	14	91	124
Other comprehensive income (loss), before tax:
Amounts before reclassifications	(74)	(15)	(175)	(136)
Amounts reclassified out	(5)	(28)	(23)	(80)
Total other comprehensive income (loss), before tax	(79)	(43)	(198)	(216)
Tax effect	28	16	71	79
Total other comprehensive income (loss), net of tax	(51)	(27)	(127)	(137)
Stockholders' Equity Attributable to 3M, Ending Balance	$ (36)	$ (13)	$ (36)	$ (13)