Leases (Details 2) - USD ($) $ in Millions	6 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Leases [Abstract]
Operating cash flows from operating leases	$ 20.2	$ 25.3
Operating cash flows from finance leases	0.1	0.1
Financing cash flows from finance leases	1.4	1.5
Right-of-use asset obtained in exchange for operating lease liabilities	0.0	16.2
Right-of-use asset obtained in exchange for finance lease liabilities	$ 0.5	$ 0.8