Stock-Based Compensation (Details 2) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	May. 31, 2012
Share- based compensation assumptions
Stock-based compensation programs expense	$ 49	$ 52	$ 187	$ 174
Stock Option Program
Stock Option Program
Balance at the beginning of the period			39,235,557
Granted - Annual			5,529,544
Exercised			(4,515,976)
Canceled			(112,047)
Balance at the end of the period	40,137,078		40,137,078
Weighted average exercise price - Beginning balance			$ 90.38
Weighted average exercise price - Granted - Annual			165.91
Weighted average exercise price - Exercised			83.22
Weighted average exercise price - Canceled			117.81
Weighted average exercise price - Ending balance	$ 101.52		$ 101.52
Expiration of annual grants			10 years
Options exercisable	28,708,664		28,708,664
Options exercisable, exercise price	$ 85.94		$ 85.94
Weighted average remaining contractual life for options outstanding			71 months
Aggregate intrinsic value for options outstanding	$ 2,182		$ 2,182
Weighted average remaining contractual life for options exercisable			57 months
Aggregate intrinsic value for options exercisable	1,963		$ 1,963
Compensation expense yet to be recognized	$ 104		$ 104
Weighted average life of remaining vesting period			25 months
Total intrinsic value of stock options exercised			$ 366	340
Cash received from options exercised			376	517
Tax benefit realized from exercise of stock options			$ 136	$ 125
Stock Option Program | Maximum
Stock Option Program
Vesting period			3 years
Stock Option Program | Minimum
Stock Option Program
Vesting period			1 year
Stock Option Program | Annual Stock Option Program
Share- based compensation assumptions
Weighted average exercise price	$ 165.94		$ 165.94
Risk-free interest rate (as a percent)			1.50%
Dividend yield (as a percent)			2.50%
Expected volatility (as a percent)			20.10%
Expected life			76 months
Black-Scholes fair value			$ 23.98
3M Long Term Incentive Plan
Share- based compensation assumptions
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)	19,824,070		19,824,070