v3.26.1
Benefit Plans (Change in benefit obligations funded status) (Details) - USD ($)
$ in Millions
 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss) $ 0.7 $ 0.1  
Equity Investments      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage 30.00%    
Other Postretirement Benefit Plans, Defined Benefit      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months $ 0.9    
Defined Benefit Plan, Benefit Obligation 5.2 5.8 $ 6.2
Defined Benefit Plan, Service Cost 0.0 0.0 0.0
Defined benefit plan, change in benefit obligation, interest cost 0.3 0.3  
Defined Benefit Plan, Actuarial Net (Gains) Losses (0.4) (0.6)  
Defined Benefit Plan, Benefit Obligation, Benefits Paid 0.5 0.1  
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant 0.0 0.0  
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31) (0.5) (0.1)  
Defined Benefit Plan, Plan Assets, Payment for Settlement 0.0 0.0  
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant 0.0 0.0  
Defined Benefit Plan, Plan Assets, Amount 0.0 0.0 0.0
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss) 0.0 0.0  
Defined Benefit Plan, Plan Assets, Contributions by Employer 0.5 0.1  
Defined Benefit Plan, Funded (Unfunded) Status of Plan (5.2) (5.8)  
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment 0.0 0.0  
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss) 0.0 0.0  
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss) 0.0 0.0  
Defined Benefit Plan, Amortization of Prior Service Cost (Credit) 0.0 0.0  
Other Defined Benefit Pension Plans [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months 6.0    
Defined Benefit Plan, Benefit Obligation 93.1 90.7 96.4
Defined Benefit Plan, Service Cost 0.7 0.7 0.7
Defined benefit plan, change in benefit obligation, interest cost 4.7 4.2  
Defined Benefit Plan, Actuarial Net (Gains) Losses (1.9) (9.1)  
Defined Benefit Plan, Benefit Obligation, Benefits Paid 6.2 4.6  
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant 0.6 1.0  
Defined Benefit Plan, Benefits Paid (Deprecated 2017-01-31) (6.0) (4.5)  
Defined Benefit Plan, Plan Assets, Payment for Settlement (0.9) 0.0  
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant 0.6 1.0  
Defined Benefit Plan, Plan Assets, Amount 112.8 109.3 $ 113.9
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss) 6.0 (4.9)  
Defined Benefit Plan, Plan Assets, Contributions by Employer 0.7 1.2  
Defined Benefit Plan, Funded (Unfunded) Status of Plan 19.7 18.6  
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Curtailment (0.9) 0.0  
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss) 3.2 2.6  
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss) 2.9 2.1  
Defined Benefit Plan, Amortization of Prior Service Cost (Credit) $ 2.4 $ 0.0