Significant Accounting Policies - Accounting Changes (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2016	Jun. 30, 2016
ASU 2016-09 Improvements to Employee Share-Based Payment Accounting \| Income Tax Benefit
New Accounting Pronouncement or Change in Accounting Principle, Current Period Disclosures [Abstract]
New accounting pronouncement income statement impact	$ 59	$ 140

This element represents the impact to the income statement related to new accounting policy adoption and/or new accounting guidance adoption.

No definition available.

Name:	mmm_NewAccountingPronouncementImpactToIncomeStatementItems
Namespace Prefix:	mmm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration