v3.26.1
Accumulated Other Comprehensive Loss (Schedule of Accumulated Other Comprehensive Loss) (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2026
Mar. 31, 2025
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning shareholders' equity $ 1,486.2 $ 1,501.0 $ 1,553.1 $ 1,584.1
OCI before reclassifications     (6.4) (22.1)
Reclassifications to earnings     1.2 (0.3)
Ending shareholders' equity 1,448.1 1,513.9 1,448.1 1,513.9
Foreign Currency Translation Adjustments        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning shareholders' equity     (41.3) (68.3)
OCI before reclassifications     (8.8) (25.3)
Reclassifications to earnings     0.0 0.0
Ending shareholders' equity (50.1) (93.6) (50.1) (93.6)
Pension and Post-retirement Activity        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning shareholders' equity     (67.6) (84.8)
OCI before reclassifications     (0.2) (0.2)
Reclassifications to earnings     1.1 0.9
Ending shareholders' equity (66.7) (84.1) (66.7) (84.1)
Accumulated other comprehensive loss        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning shareholders' equity (104.5) (197.7) (109.8) (154.8)
Ending shareholders' equity (115.0) (177.2) (115.0) (177.2)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning shareholders' equity     (0.9) (1.7)
OCI before reclassifications     2.6 3.4
Reclassifications to earnings     0.1 (1.2)
Ending shareholders' equity $ 1.8 $ 0.5 $ 1.8 $ 0.5