Leases (Details 1) - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2020
Leases [Abstract]
Operating lease cost	$ 43.8	$ 45.4	$ 51.7
Finance lease cost:
Amortization of right-of-use assets	2.0	2.4	2.8
Interest on lease liabilities	0.1	0.1	0.2
Variable lease cost	21.6	23.2	22.9
Short-term lease cost	43.5	37.6	35.2
Sublease income	(1.5)	(3.7)	(4.3)
Net lease cost	$ 109.5	$ 105.0	$ 108.5