Stock-Based Compensation (Details 2) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 Stock Option Program	Jun. 30, 2013 Stock Option Program	Jun. 30, 2014 Stock Option Program Maximum	Jun. 30, 2014 Stock Option Program Minimum	Jun. 30, 2014 Stock Option Program Annual Stock Option Program	Jun. 30, 2014 3M Long Term Incentive Plan	May 31, 2012 3M Long Term Incentive Plan
Stock Option Program
Balance at the beginning of the period					43,938,778
Granted - Annual					5,736,183
Exercised					(6,229,925)
Canceled					(154,922)
Balance at the end of the period					43,290,114
Weighted average exercise price - Beginning balance					$ 83.84
Weighted average exercise price - Granted - Annual					$ 126.77
Weighted average exercise price - Exercised					$ 83.02
Weighted average exercise price - Canceled					$ 103.29
Weighted average exercise price - Ending balance					$ 89.58
Vesting period							3 years	1 year
Expiration of annual grants					10 years
Options exercisable					31,486,006
Options exercisable, exercise price					$ 81.41
Weighted average remaining contractual life for options outstanding					68 months
Aggregate intrinsic value for options outstanding					$ 2,323
Weighted average remaining contractual life for options exercisable					53 months
Aggregate intrinsic value for options exercisable					1,947
Compensation expense yet to be recognized					89
Weighted average life of remaining vesting period					25 months
Total intrinsic value of stock options exercised					340	338
Cash received from options exercised					517	1,039
Tax benefit realized from exercise of stock options					125	125
Share- based compensation assumptions
Weighted average exercise price									$ 126.72
Risk-free interest rate (as a percent)									1.90%
Dividend yield (as a percent)									2.60%
Expected volatility (as a percent)									20.80%
Expected life									75 months
Black-Scholes fair value									$ 19.63
Stock-based compensation programs expense	$ 52	$ 47	$ 174	$ 150
Number of shares authorized											100,000,000
Number of shares available for grant under the 2008 Long Term Incentive Plan Program (including additional subsequent shareholder approvals)										28,813,481