Supplemental Equity and Comprehensive Income Information - AOCI rf (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
AOCI Attributable to 3M, Net of Tax [Roll Forward]
Stockholders' Equity Attributable to 3M, Beginning Balance			$ 11,708
Other comprehensive income (loss), before tax:
Stockholders' Equity Attributable to 3M, Ending Balance	$ 11,894		11,894
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to 3M, Net of Tax [Roll Forward]
Stockholders' Equity Attributable to 3M, Beginning Balance	(6,261)	$ (6,321)	(6,359)	$ (6,289)
Other comprehensive income (loss), before tax:
Amounts before reclassifications	44	(28)	(17)	88
Amounts reclassified out	73	107	124	204
Total other comprehensive income (loss), before tax	117	79	107	292
Tax effect	(40)	9	68	(236)
Total other comprehensive income (loss), net of tax	77	88	175	56
Stockholders' Equity Attributable to 3M, Ending Balance	(6,184)	(6,233)	(6,184)	(6,233)
Cumulative Translation Adjustment
AOCI Attributable to 3M, Net of Tax [Roll Forward]
Stockholders' Equity Attributable to 3M, Beginning Balance	(1,540)	(1,288)	(1,679)	(1,095)
Other comprehensive income (loss), before tax:
Amounts before reclassifications	59	(12)	119	(56)
Total other comprehensive income (loss), before tax	59	(12)	119	(56)
Tax effect	(22)	36	57	(113)
Total other comprehensive income (loss), net of tax	37	24	176	(169)
Stockholders' Equity Attributable to 3M, Ending Balance	(1,503)	(1,264)	(1,503)	(1,264)
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	(4,735)	(5,202)	(4,804)	(5,293)
Other comprehensive income (loss), before tax:
Amounts before reclassifications				24
Amounts reclassified out	101	141	204	265
Total other comprehensive income (loss), before tax	101	141	204	289
Tax effect	(34)	(45)	(68)	(102)
Total other comprehensive income (loss), net of tax	67	96	136	187
Stockholders' Equity Attributable to 3M, Ending Balance	(4,668)	(5,106)	(4,668)	(5,106)
Cash flow hedging instruments gains (losses)
AOCI Attributable to 3M, Net of Tax [Roll Forward]
Stockholders' Equity Attributable to 3M, Beginning Balance	14	169	124	99
Other comprehensive income (loss), before tax:
Amounts before reclassifications	(15)	(16)	(136)	120
Amounts reclassified out	(28)	(34)	(80)	(61)
Total other comprehensive income (loss), before tax	(43)	(50)	(216)	59
Tax effect	16	18	79	(21)
Total other comprehensive income (loss), net of tax	(27)	(32)	(137)	38
Stockholders' Equity Attributable to 3M, Ending Balance	$ (13)	$ 137	$ (13)	$ 137