This amount represents the components of net periodic benefit costs (benefits) (such as interest, expected return on plan assets, prior service cost amortization and actuarial gain/loss) that no longer will be included within operating expense after adoption of ASU No. 2017-07.

No definition available.

Name:	mmm_AmountOfNetPeriodicBenefitCostNoLongerIncludedWithinOperatingExpense
Namespace Prefix:	mmm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Significant Accounting Policies - New Accounting Pronouncements (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
ASU 2016-01 Recognition and Measurement of Financial Assets and Financial Liabilities \| Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Approximate equity securities and cost method investments in aggregate	$ 75		$ 75
ASU 2017-07 Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Amount of net periodic benefit costs (benefits) that will no longer be included within operating expenses once ASU No. 2017-07 is adopted.	$ (32)	$ (54)	$ (64)	$ (106)