Special Project Costs - Narrative (Details) - 2021 Restructuring Program - USD ($) $ in Millions	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred noncash charge	$ 10.2	$ 18.6	$ 4.4
Restructuring and related cost, noncash charge incurred to date	33.2
Restructuring and related cost, incurred cost	11.1	28.5	24.1
Employee-related costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, incurred cost	3.5	6.3	$ 17.3
Restructuring Reserve	$ 1.6	$ 2.4