Goodwill and Intangible Assets - Definite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2021	Apr. 30, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 647,973	$ 592,098
Accumulated Amortization	(358,471)	(291,581)
Net Carrying Value	$ 289,502	$ 300,517
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	13 years 3 months 18 days	12 years 9 months 18 days
Gross Carrying Amount	$ 569,255	$ 516,928
Accumulated Amortization	(330,880)	(270,029)
Net Carrying Value	$ 238,375	$ 246,899
Customer relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Lives (years)	5 years	5 years
Customer relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Lives (years)	16 years	16 years
Definite-lived tradenames
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	16 years 9 months 18 days	16 years 3 months 18 days
Gross Carrying Amount	$ 62,084	$ 55,654
Accumulated Amortization	(14,842)	(10,474)
Net Carrying Value	$ 47,242	$ 45,180
Definite-lived tradenames | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Lives (years)	5 years	5 years
Definite-lived tradenames | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Lives (years)	20 years	20 years
Vendor agreements
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	8 years 3 months 18 days	8 years 3 months 18 days
Gross Carrying Amount	$ 6,644	$ 6,644
Accumulated Amortization	(5,372)	(4,567)
Net Carrying Value	$ 1,272	$ 2,077
Vendor agreements | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Lives (years)	8 years	8 years
Vendor agreements | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Lives (years)	10 years	10 years
Developed technology
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Lives (years)	5 years	5 years
Weighted Average Amortization Period (in years)	4 years 10 months 24 days	4 years 10 months 24 days
Gross Carrying Amount	$ 5,699	$ 5,036
Accumulated Amortization	(3,381)	(1,963)
Net Carrying Value	$ 2,318	$ 3,073
Other
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (in years)	3 years 3 months 18 days	5 years 3 months 18 days
Gross Carrying Amount	$ 4,291	$ 7,836
Accumulated Amortization	(3,996)	(4,548)
Net Carrying Value	$ 295	$ 3,288
Other | Minimum
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Lives (years)	3 years	1 year
Other | Maximum
Finite-Lived Intangible Assets [Line Items]
Estimated Useful Lives (years)	5 years	15 years