v3.26.1
Accumulated Other Comprehensive Loss (Changes In Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2026
Jun. 30, 2025
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]          
Beginning balance       $ 2,266.3  
Ending balance $ 2,556.4     2,556.4  
Amounts reclassified from accumulated other comprehensive loss, tax 1.1   $ 0.6 2.1 $ 1.2
Foreign Currency [Member]          
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]          
Beginning balance (20.2) $ (26.0) (26.2) (16.4) (26.2)
Other comprehensive (loss) income before reclassifications (4.8) 10.3   (8.6) 10.5
Amounts reclassified from accumulated other comprehensive income (net of tax)  
Net current-period other comprehensive (loss) income (4.8) 10.3   (8.6) 10.5
Ending balance (25.0) (15.7) (26.0) (25.0) (15.7)
Pension and Other Postretirement Benefits [Member]          
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]          
Beginning balance (181.6) (189.7) (191.5) (184.7) (191.5)
Other comprehensive (loss) income before reclassifications  
Amounts reclassified from accumulated other comprehensive income (net of tax) 2.9 1.9   6.0 3.7
Net current-period other comprehensive (loss) income 2.9 1.9   6.0 3.7
Ending balance (178.7) (187.8) (189.7) (178.7) (187.8)
Accumulated Other Comprehensive Loss [Member]          
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]          
Beginning balance (201.8) (215.7) (217.7) (201.1) (217.7)
Other comprehensive (loss) income before reclassifications (4.8) 10.3   (8.6) 10.5
Amounts reclassified from accumulated other comprehensive income (net of tax) 2.9 1.9   6.0 3.7
Net current-period other comprehensive (loss) income (1.9) 12.2   (2.6) 14.2
Ending balance $ (203.7) $ (203.5) $ (215.7) $ (203.7) $ (203.5)