v3.26.1
Supplemental Equity and Comprehensive Income Information - Schedule of AOCI Rollforward (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
AOCI Attributable to 3M, Net of Tax Roll Forward    
Balance at the beginning of the period $ 4,747 $ 3,894
Other comprehensive income (loss), before tax:    
Total other comprehensive income (loss), net of tax (33) 200
Balance at the end of the period 3,311 4,523
Total accumulated other comprehensive income (loss)    
AOCI Attributable to 3M, Net of Tax Roll Forward    
Balance at the beginning of the period (5,069) (5,731)
Other comprehensive income (loss), before tax:    
Amounts before reclassifications (54) 135
Amounts reclassified out 71 53
Total other comprehensive income (loss), before tax 17 188
Tax effect (47) 12
Total other comprehensive income (loss), net of tax (30) 200
Balance at the end of the period (5,099) (5,531)
Cumulative translation adjustment    
AOCI Attributable to 3M, Net of Tax Roll Forward    
Balance at the beginning of the period (2,520) (2,953)
Other comprehensive income (loss), before tax:    
Amounts before reclassifications (67) 149
Amounts reclassified out 0 0
Total other comprehensive income (loss), before tax (67) 149
Tax effect (25) 22
Total other comprehensive income (loss), net of tax (92) 171
Balance at the end of the period (2,612) (2,782)
Defined benefit pension and postretirement plans adjustment    
AOCI Attributable to 3M, Net of Tax Roll Forward    
Balance at the beginning of the period (2,451) (2,763)
Other comprehensive income (loss), before tax:    
Amounts before reclassifications 0 0
Amounts reclassified out 63 76
Total other comprehensive income (loss), before tax 63 76
Tax effect (16) (18)
Total other comprehensive income (loss), net of tax 47 58
Balance at the end of the period (2,404) (2,705)
Cash flow hedging instruments, unrealized gain (loss)    
AOCI Attributable to 3M, Net of Tax Roll Forward    
Balance at the beginning of the period (98) (15)
Other comprehensive income (loss), before tax:    
Amounts before reclassifications 13 (14)
Amounts reclassified out 8 (23)
Total other comprehensive income (loss), before tax 21 (37)
Tax effect (6) 8
Total other comprehensive income (loss), net of tax 15 (29)
Balance at the end of the period $ (83) $ (44)