Income Taxes, Unrecognized Tax Benefits (Details) - USD ($) $ in Millions		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Reconciliation of unrecognized tax benefits [Roll Forward]
Beginning balance		$ 13.6	$ 14.2
Gross increases - tax positions in prior period		1.6	0.8
Gross decreases - tax positions in prior period		(0.2)	(1.2)	[1]
Gross increases - due to acquisition		0.0	1.4
Gross increases - tax positions in current period		1.1	0.5
Settlements		(0.1)	(0.3)
Lapse of statute of limitations		(2.2)	(1.8)
Ending balance		13.8	13.6
Unrecognized tax benefits that would impact effective tax rate		12.2
Unrecognized tax benefits accrued interest and penalties		$ 1.1	1.0
Change in income tax expense (benefit) due to the reduction of federal corporate tax			$ 1.0
Forecast [Member]
Reconciliation of unrecognized tax benefits [Roll Forward]
Lapse of statute of limitations	$ (0.2)

[1] Fiscal 2018 includes $1.0 million related to the reduction of the U.S. federal corporate tax rate as a result of the Tax Act.