v3.26.1
Accumulated Other Comprehensive Loss (Schedule of Reclassifications out of Accumulated Other Comprehensive Loss) (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Mar. 31, 2026
Dec. 31, 2025
Sep. 30, 2025
Mar. 31, 2025
Dec. 31, 2024
Sep. 30, 2024
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                    
OCI gain (loss) on cash flow hedge, reclassification before tax $ 0.7 $ (0.2) $ 0.5 $ 1.5            
Reclassification to earnings     (1.3) (0.2)            
Gain (Loss) from Litigation Settlement 0.0 0.0 5.7 0.0            
Accumulated other comprehensive loss (115.1)   (115.1)       $ (109.8)      
Stockholders' Equity Attributable to Parent 1,459.9 1,568.0 1,459.9 1,568.0 $ 1,448.1 $ 1,486.2 1,553.1 $ 1,513.9 $ 1,501.0 $ 1,584.1
OCI before reclassifications     (6.6) 27.7            
Foreign Currency Translation Adjustments                    
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                    
Reclassification to earnings     0.0 0.0            
Stockholders' Equity Attributable to Parent (51.7) (40.1) (51.7) (40.1)     (41.3)     (68.3)
OCI before reclassifications     (10.4) 28.2            
Pension and Post-retirement Activity                    
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                    
Reclassification to earnings     (1.6) (1.3)            
Stockholders' Equity Attributable to Parent (66.3) (83.6) (66.3) (83.6)     (67.6)     (84.8)
OCI before reclassifications     (0.3) (0.1)            
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent                    
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                    
Reclassification to earnings     0.3 1.1            
Stockholders' Equity Attributable to Parent 2.9 (3.2) 2.9 (3.2)     (0.9)     (1.7)
OCI before reclassifications     4.1 (0.4)            
Accumulated other comprehensive loss                    
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                    
Stockholders' Equity Attributable to Parent (115.1) (126.9) (115.1) (126.9) $ (115.0) $ (104.5) $ (109.8) $ (177.2) $ (197.7) $ (154.8)
Reclassification out of Accumulated Other Comprehensive Income                    
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                    
OCI gain (loss) on cash flow hedge, reclassification before tax 0.6 (0.2)                
OCI gain (loss) on cash flow hedge, reclassification, tax 0.2 (0.1) 0.1 0.4            
Amortization of defined benefit pension and postretirement items, tax (0.2) (0.2) (0.5) (0.5)            
Amortization of defined benefit pension and postretirement items, after tax (0.5) (0.4) (1.6) (1.3)            
Reclassification to earnings (0.1) (0.5) (1.3) (0.2)            
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax (0.4) 0.1 0.3 1.1            
Amortization of defined benefit pension and postretirement items, actuarial losses, before tax $ (0.7) $ (0.6) (2.1) [1] (1.8)            
Reclassification out of Accumulated Other Comprehensive Income | Nonoperating Income (Expense)                    
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]                    
OCI gain (loss) on cash flow hedge, reclassification before tax     $ 0.4 $ 1.5            
[1] These AOCI components are included in the computation of net periodic benefit cost. See Note 13 of Notes to Condensed Consolidated Financial Statements.