Goodwill and Intangible Assets - Narrative (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Apr. 30, 2020 USD ($)	Apr. 30, 2021 USD ($) unit	Apr. 30, 2020 USD ($)	Apr. 30, 2019 USD ($)
Finite-Lived Intangible Assets [Line Items]
Number of reporting units | unit		8
Impairment of goodwill	$ (63,100)	$ 0	$ (63,074)	$ 0
Goodwill	553,073	576,330	553,073
Amortization expense		57,645	65,201	71,003
Tradenames	61,400	61,400	61,400
Canada
Finite-Lived Intangible Assets [Line Items]
Impairment of goodwill	$ (63,100)
Goodwill		144,600
Depreciation and amortization expense
Finite-Lived Intangible Assets [Line Items]
Amortization expense		$ 57,600	$ 65,200	$ 71,000