Significant Accounting Policies - Earnings Per Share Computations (Details) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2023 USD ($) $ / shares shares	Mar. 31, 2023 division	Sep. 30, 2022 USD ($) $ / shares shares	Sep. 30, 2023 USD ($) segment $ / shares shares	Sep. 30, 2022 USD ($) $ / shares shares	Dec. 31, 2022 division
Accounting Policies [Abstract]
Number of business segments		3		4		4
Earnings per share
Options outstanding not included in computation of diluted earnings per share (in shares)	35.6		31.7	36.0	28.9
Numerator:
Net income (loss) attributable to 3M | $	$ (2,075)		$ 3,859	$ (7,940)	$ 5,236
Denominator:
Denominator for weighted average 3M common shares outstanding - basic (in shares)	554.3		568.8	553.7	570.7
Dilution associated with the Company's stock-based compensation plans (in shares)	0.0		1.2	0.0	1.9
Denominator for weighted average 3M common shares outstanding - diluted (in shares)	554.3		570.0	553.7	572.6
Earnings (loss) per share attributable to 3M common shareholders — basic (in dollars per share) | $ / shares	$ (3.74)		$ 6.79	$ (14.34)	$ 9.18
Earnings (loss) per share attributable to 3M common shareholders — diluted (in dollars per share) | $ / shares	$ (3.74)		$ 6.77	$ (14.34)	$ 9.15