v3.26.1
Accumulated Other Comprehensive Loss (Schedule of Accumulated Other Comprehensive Loss) (Details) - USD ($)
$ in Millions
 9 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Mar. 31, 2026
Dec. 31, 2025
Sep. 30, 2025
Mar. 31, 2025
Dec. 31, 2024
Sep. 30, 2024
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Beginning Balance $ (109.8)              
OCI before reclassifications (6.6) $ 27.7            
Reclassification to earnings 1.3 0.2            
Ending Balance (115.1)              
Stockholders' Equity Attributable to Parent 1,459.9 1,568.0 $ 1,448.1 $ 1,486.2 $ 1,553.1 $ 1,513.9 $ 1,501.0 $ 1,584.1
Foreign Currency Translation Adjustments                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
OCI before reclassifications (10.4) 28.2            
Reclassification to earnings 0.0 0.0            
Stockholders' Equity Attributable to Parent (51.7) (40.1)     (41.3)     (68.3)
Pension and Post-retirement Activity                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
OCI before reclassifications (0.3) (0.1)            
Reclassification to earnings 1.6 1.3            
Stockholders' Equity Attributable to Parent (66.3) (83.6)     (67.6)     (84.8)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
OCI before reclassifications 4.1 (0.4)            
Reclassification to earnings (0.3) (1.1)            
Stockholders' Equity Attributable to Parent 2.9 (3.2)     (0.9)     (1.7)
Accumulated other comprehensive loss                
AOCI Attributable to Parent, Net of Tax [Roll Forward]                
Stockholders' Equity Attributable to Parent $ (115.1) $ (126.9) $ (115.0) $ (104.5) $ (109.8) $ (177.2) $ (197.7) $ (154.8)