Leases (Details) - USD ($) $ in Millions	Jan. 31, 2021	Apr. 30, 2020
Operating lease right-of-use assets	$ 147.9	$ 148.4
Current operating lease liabilities	39.2	36.5
Noncurrent operating lease liabilities	120.2	120.0
Total operating lease liabilities	159.4	156.5
Total finance lease liabilities	4.7	5.7
Machinery and Equipment [Member]
Machinery and equipment	9.9	11.6
Accumulated Depreciation [Member]
Accumulated depreciation	(5.3)	(5.9)
Property, Plant and Equipment [Member]
Total property, plant, and equipment	4.6	5.7
Other Current Liabilities [Member]
Current finance lease liabilities	2.0	2.2
Other Noncurrent Liabilities [Member]
Noncurrent finance lease liabilities	$ 2.7	$ 3.5