Intangible Assets - Summary of Intangible Assets (Details) - USD ($) $ in Thousands	Apr. 30, 2021	Apr. 30, 2020
Intangible Assets Excluding Goodwill [Line Items]
Total definite-lived intangible assets, Gross Carrying Amount	$ 163,474	$ 162,905
Total definite-lived intangible assets, Accumulated Amortization	(110,261)	(93,957)
Total definite-lived intangible assets, Net Carrying Amount	53,213	68,948
Indefinite-lived intangible assets, Net Carrying Amount	430	204
Total Intangible assets, Gross Carrying Amount	163,904	163,109
Total Intangible assets, Net Carrying Amount	53,643	69,152
Customer Relationships
Intangible Assets Excluding Goodwill [Line Items]
Total definite-lived intangible assets, Gross Carrying Amount	89,980	89,980
Total definite-lived intangible assets, Accumulated Amortization	(60,347)	(51,049)
Total definite-lived intangible assets, Net Carrying Amount	29,633	38,931
Developed Technology
Intangible Assets Excluding Goodwill [Line Items]
Total definite-lived intangible assets, Gross Carrying Amount	21,588	21,588
Total definite-lived intangible assets, Accumulated Amortization	(14,456)	(12,529)
Total definite-lived intangible assets, Net Carrying Amount	7,132	9,059
Patents, Trademarks, and Trade Names
Intangible Assets Excluding Goodwill [Line Items]
Total definite-lived intangible assets, Gross Carrying Amount	50,007	49,697
Total definite-lived intangible assets, Accumulated Amortization	(34,308)	(29,229)
Total definite-lived intangible assets, Net Carrying Amount	15,699	20,468
Backlog
Intangible Assets Excluding Goodwill [Line Items]
Total definite-lived intangible assets, Gross Carrying Amount	1,150	1,150
Total definite-lived intangible assets, Accumulated Amortization	(1,150)	(1,150)
Definite-lived Intangible Assets Excluding Patents in Progress
Intangible Assets Excluding Goodwill [Line Items]
Total definite-lived intangible assets, Gross Carrying Amount	162,725	162,415
Total definite-lived intangible assets, Accumulated Amortization	(110,261)	(93,957)
Total definite-lived intangible assets, Net Carrying Amount	52,464	68,458
Patents in Progress
Intangible Assets Excluding Goodwill [Line Items]
Total definite-lived intangible assets, Gross Carrying Amount	749	490
Total definite-lived intangible assets, Net Carrying Amount	$ 749	$ 490