Intangibles (Schedule of Intangible Assets) (Details) - USD ($) $ in Thousands	Jan. 31, 2020	Apr. 30, 2019
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Intangibles, gross	$ 274,000	$ 274,000
Less accumulated amortization	(95,139)	(60,889)
Intangibles, net	178,861	213,111
Trademarks
Finite-Lived Intangible Assets [Line Items]
Intangibles, gross	10,000	10,000
Less accumulated amortization	(6,944)	(4,445)
Intangibles, net	$ 3,056	$ 5,555