Stock-Based Compensation (Details)	9 Months Ended
Sep. 30, 2013
Stock-Based Compensation
Retirement age eligibility for employees	55 years
Retirement eligibility for employees, minimum years of service required	5 years
Percent of stock-based compensation related to retiree-eligible population (as a percent)	32.00%

The age at which employees of the entity are eligible for retirement, which combined with reaching years of service triggers expense recognition of share based compensation expense, in years.

No definition available.

Name:	mmm_ShareBasedCompensationArrangementByShareBasedPaymentAwardExpenseRecognitionEligibleForRetirementAge
Namespace Prefix:	mmm_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration