v3.26.3
Accumulated other comprehensive income (loss) - Reclasses out of AOCI (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Jun. 30, 2026
Mar. 31, 2026
Sep. 30, 2025
Jun. 30, 2025
Mar. 31, 2025
Sep. 30, 2026
Sep. 30, 2025
Other Comprehensive Income (Loss), Net of Tax [Abstract]                
Beginning balance $ 442.4 $ 393.1 $ 407.3 $ 385.1 $ 329.0 $ 312.5 $ 407.3 $ 312.5
Other comprehensive income (loss) (27.2) 6.5 0.4 6.5 93.2 38.5 (20.3) 138.2
Dispositions of noncontrolling interests [1] 43.6              
Ending balance 384.0 $ 442.4 393.1 396.5 385.1 329.0 384.0 396.5
AOCI Attributable to Parent                
Other Comprehensive Income (Loss), Net of Tax [Abstract]                
Beginning balance     (665.6) (677.2) (766.5) (804.1) (665.6) (804.1)
Other comprehensive income (loss) before reclassifications             (21.2)  
Amounts reclassified from accumulated other comprehensive loss to net income             2.8  
Other comprehensive income (loss) (26.4)     7.1 89.3 37.8 (18.4) 134.2
Dispositions of noncontrolling interests (3.4) [1]           3.4  
Ending balance (680.6)     (670.1) $ (677.2) $ (766.5) (680.6) (670.1)
Benefit Plan Adjustments                
Other Comprehensive Income (Loss), Net of Tax [Abstract]                
Beginning balance     (267.0)       (267.0)  
Other comprehensive income (loss) before reclassifications             (0.3)  
Amounts reclassified from accumulated other comprehensive loss to net income             6.8  
Other comprehensive income (loss) 2.6     (0.2)     6.5 (3.7)
Dispositions of noncontrolling interests             0.0  
Ending balance (260.5)           (260.5)  
Foreign Currency Translation Adjustments                
Other Comprehensive Income (Loss), Net of Tax [Abstract]                
Beginning balance     (406.8)       (406.8)  
Other comprehensive income (loss) before reclassifications             (21.5)  
Amounts reclassified from accumulated other comprehensive loss to net income             (3.1)  
Other comprehensive income (loss) (28.4)     9.3     (24.6) 141.9
Dispositions of noncontrolling interests             3.4  
Ending balance (428.0)           (428.0)  
Gains (losses) on available-for-sale securities                
Other Comprehensive Income (Loss), Net of Tax [Abstract]                
Beginning balance     (0.9)       (0.9)  
Other comprehensive income (loss) before reclassifications             (0.6)  
Amounts reclassified from accumulated other comprehensive loss to net income             1.6  
Other comprehensive income (loss) 0.0     (0.8)     1.0 1.0
Dispositions of noncontrolling interests             0.0  
Ending balance 0.1           0.1  
Gains (Losses) on Cash Flow Hedges                
Other Comprehensive Income (Loss), Net of Tax [Abstract]                
Beginning balance     $ 9.1       9.1  
Other comprehensive income (loss) before reclassifications             1.2  
Amounts reclassified from accumulated other comprehensive loss to net income             (2.5)  
Other comprehensive income (loss) (0.6)     $ (1.2)     (1.3) $ (5.0)
Dispositions of noncontrolling interests             0.0  
Ending balance $ 7.8           $ 7.8  
[1] This amount primarily represents the impact of transactions in which we acquired or disposed of noncontrolling ownership interests in certain companies where we had an existing controlling interest prior to and after the related acquisition or disposal transactions. During the third quarter ended September 30, 2026, we disposed of our noncontrolling ownership interests associated with our Malaysia operations following their deconsolidation effective July 1, 2026.