Leases (Details 2) - USD ($) $ in Millions	3 Months Ended
	Jul. 31, 2020	Jul. 31, 2019
Leases [Abstract]
Operating cash flows from operating leases	$ 10.4	$ 13.1
Operating cash flows from finance leases	0.0	0.1
Financing cash flows from finance leases	0.9	0.7
Right-of-use asset obtained in exchange for operating lease liabilities	0.0	0.0
Right-of-use asset obtained in exchange for finance lease liabilities	$ 0.3	$ 0.5