Supplemental Equity and Comprehensive Income Information - AOCI rf (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 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	$ 12,002		12,002
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to 3M, Net of Tax [Roll Forward]
Stockholders' Equity Attributable to 3M, Beginning Balance	(6,184)	$ (6,233)	(6,359)	$ (6,289)
Other comprehensive income (loss), before tax:
Amounts before reclassifications	(52)	(187)	(69)	(99)
Amounts reclassified out	79	79	203	283
Total other comprehensive income (loss), before tax	27	(108)	134	184
Tax effect	11	(126)	79	(362)
Total other comprehensive income (loss), net of tax	38	(234)	213	(178)
Stockholders' Equity Attributable to 3M, Ending Balance	(6,146)	(6,467)	(6,146)	(6,467)
Cumulative Translation Adjustment
AOCI Attributable to 3M, Net of Tax [Roll Forward]
Stockholders' Equity Attributable to 3M, Beginning Balance	(1,503)	(1,264)	(1,679)	(1,095)
Other comprehensive income (loss), before tax:
Amounts before reclassifications	(8)	(477)	111	(533)
Total other comprehensive income (loss), before tax	(8)	(477)	111	(533)
Tax effect	24	6	81	(107)
Total other comprehensive income (loss), net of tax	16	(471)	192	(640)
Stockholders' Equity Attributable to 3M, Ending Balance	(1,487)	(1,735)	(1,487)	(1,735)
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	(4,668)	(5,106)	(4,804)	(5,293)
Other comprehensive income (loss), before tax:
Amounts before reclassifications		233		257
Amounts reclassified out	103	134	307	399
Total other comprehensive income (loss), before tax	103	367	307	656
Tax effect	(36)	(131)	(104)	(233)
Total other comprehensive income (loss), net of tax	67	236	203	423
Stockholders' Equity Attributable to 3M, Ending Balance	(4,601)	(4,870)	(4,601)	(4,870)
Cash flow hedging instruments gains (losses)
AOCI Attributable to 3M, Net of Tax [Roll Forward]
Stockholders' Equity Attributable to 3M, Beginning Balance	(13)	137	124	99
Other comprehensive income (loss), before tax:
Amounts before reclassifications	(44)	57	(180)	177
Amounts reclassified out	(24)	(55)	(104)	(116)
Total other comprehensive income (loss), before tax	(68)	2	(284)	61
Tax effect	23	(1)	102	(22)
Total other comprehensive income (loss), net of tax	(45)	1	(182)	39
Stockholders' Equity Attributable to 3M, Ending Balance	$ (58)	$ 138	$ (58)	$ 138