Integration and Restructuring Costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2021	Jan. 31, 2020	Apr. 30, 2020
Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	$ 60.0		$ 60.0
Restructuring Plan [Member] | Employee-related costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	1.7		1.7
Restructuring Reserve	1.4		1.4
Ainsworth [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Cost Incurred to Date					$ 48.6
Restructuring and Related Cost, Noncash Charge Incurred to Date					4.7
Restructuring and Related Cost, Incurred Cost	$ 0.0	$ 3.3	$ 0.0	$ 9.9
Ainsworth [Member] | Employee-related costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve					$ 0.5