v3.26.1
Benefit Plans Benefit Plans (Rollforward of Level 3 assets) (Details) - USD ($)
$ in Millions
12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Defined Benefit Plan Disclosure [Line Items]      
Other Investments $ 7.8 $ 6.9 $ 6.1
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Period Increase (Decrease)   0.1  
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss) 0.7 0.1  
Fair Value, Inputs, Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Assets Transferred into (out of) Level 3 $ 0.2 $ 0.6