v3.25.2
Accumulated other comprehensive income (loss) - Reclasses Out Of AOCI (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2024
Mar. 31, 2024
Jun. 30, 2025
Jun. 30, 2024
Other Comprehensive Income (Loss), Net of Tax [Abstract]            
Beginning balance $ 329.0 $ 312.5 $ 519.9 $ 520.2 $ 312.5 $ 520.2
Other comprehensive income (loss) 93.2 38.5 (75.9) (14.8) 131.7 (90.7)
Acquisitions of noncontrolling interests   (6.6) [1]   (0.2) [2]    
Ending balance 385.1 329.0 446.6 519.9 385.1 446.6
AOCI Attributable to Parent            
Other Comprehensive Income (Loss), Net of Tax [Abstract]            
Beginning balance (766.5) (804.1) (669.0) (656.0) (804.1) (656.0)
Other comprehensive income (loss) before reclassifications         125.8  
Amounts reclassified from accumulated other comprehensive loss to net income         1.3  
Other comprehensive income (loss) 89.3 37.8 (75.0) (13.0) 127.1 (88.0)
Acquisitions of noncontrolling interests   (0.2) [1]     (0.2)  
Ending balance (677.2) (766.5) (744.0) $ (669.0) (677.2) (744.0)
Benefit Plan Adjustments            
Other Comprehensive Income (Loss), Net of Tax [Abstract]            
Beginning balance   (260.4)     (260.4)  
Other comprehensive income (loss) before reclassifications         (5.6)  
Amounts reclassified from accumulated other comprehensive loss to net income         2.1  
Other comprehensive income (loss) (1.9)   (4.3)   (3.5) (3.3)
Ending balance (263.9)       (263.9)  
Foreign Currency Translation Adjustments            
Other Comprehensive Income (Loss), Net of Tax [Abstract]            
Beginning balance   (556.7)     (556.7)  
Other comprehensive income (loss) before reclassifications         134.4  
Amounts reclassified from accumulated other comprehensive loss to net income         (1.8)  
Other comprehensive income (loss) 91.9   (71.6)   132.6 (93.2)
Acquisitions of noncontrolling interests         (0.2)  
Ending balance (424.3)       (424.3)  
Gains (losses) on available-for-sale securities            
Other Comprehensive Income (Loss), Net of Tax [Abstract]            
Beginning balance   (3.3)     (3.3)  
Other comprehensive income (loss) before reclassifications         (2.7)  
Amounts reclassified from accumulated other comprehensive loss to net income         4.5  
Other comprehensive income (loss) 1.1   0.2   1.8 (0.6)
Ending balance (1.5)       (1.5)  
Gains (Losses) on Cash Flow Hedges            
Other Comprehensive Income (Loss), Net of Tax [Abstract]            
Beginning balance   $ 16.3     16.3  
Other comprehensive income (loss) before reclassifications         (0.3)  
Amounts reclassified from accumulated other comprehensive loss to net income         (3.5)  
Other comprehensive income (loss) (1.8)   $ 0.7   (3.8) $ 9.1
Ending balance $ 12.5       $ 12.5  
[1] This amount 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.
[2] This amount 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.