v3.26.1
Changes in Accumulated Other Comprehensive Loss (Classification Of Accumulated Other Comprehensive Income Reflected On Consolidated Balance Sheets) (Detail) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Increase (Decrease) in Stockholders' Equity [Roll Forward]    
Balance, beginning of period $ 2,063.4  
Balance, end of period 2,179.9  
Deferred tax assets, other comprehensive loss 81.6 $ 83.3
Defined Benefit Pension and Postretirement Items    
Increase (Decrease) in Stockholders' Equity [Roll Forward]    
Balance, beginning of period (213.8)  
Other comprehensive income before reclassifications 0.0  
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent 4.8  
Balance, end of period (209.0)  
Defined Benefit Pension and Postretirement Items | Reclassification out of Accumulated Other Comprehensive Income    
Increase (Decrease) in Stockholders' Equity [Roll Forward]    
Amounts reclassified from accumulated other comprehensive loss 4.8  
Currency Translation Adjustment    
Increase (Decrease) in Stockholders' Equity [Roll Forward]    
Balance, beginning of period 233.8  
Other comprehensive income before reclassifications (28.1)  
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent (28.1)  
Balance, end of period 205.7  
Currency Translation Adjustment | Reclassification out of Accumulated Other Comprehensive Income    
Increase (Decrease) in Stockholders' Equity [Roll Forward]    
Amounts reclassified from accumulated other comprehensive loss 0.0  
Accumulated Other Comprehensive Loss    
Increase (Decrease) in Stockholders' Equity [Roll Forward]    
Balance, beginning of period 20.0  
Other comprehensive income before reclassifications (28.1)  
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent (23.3)  
Balance, end of period (3.3)  
Accumulated Other Comprehensive Loss | Reclassification out of Accumulated Other Comprehensive Income    
Increase (Decrease) in Stockholders' Equity [Roll Forward]    
Amounts reclassified from accumulated other comprehensive loss $ 4.8