Income Taxes, Income Tax Provision (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2023
Federal [Abstract]
Current	$ 4.7	$ 1.6	$ 1.5
Deferred	5.8	7.1	(47.5)
State [Abstract]
Current	4.5	2.4	2.3
Deferred	(2.2)	(0.9)	(11.4)
Foreign [Abstract]
Current	52.8	41.0	27.5
Deferred	2.9	0.0	(0.7)
Total income tax provision (benefit)	$ 68.5	$ 51.2	$ (28.3)