Goodwill and intangible assets, net - Components (Details) - USD ($) $ in Thousands	Jul. 31, 2025	Jul. 31, 2024	Jul. 31, 2023
Finite Lived And Indefinite Lived Intangible Assets By Major Class [Line Items]
Goodwill, gross carrying amount	$ 257,155	$ 257,006
Goodwill, net	257,155	257,006	$ 257,006
Amortizable intangible assets, gross carrying amount	422,247	420,029
Amortizable intangible assets, accumulated amortization	(366,817)	(358,895)
Amortizable intangible assets, net	55,430	61,134
Intangible assets gross excluding goodwill	473,268	471,050
Intangible assets amortization and impairment net excluding goodwill	(366,817)	(358,895)
Intangible assets net excluding goodwill	106,451	112,155
Trade names & trademarks
Finite Lived And Indefinite Lived Intangible Assets By Major Class [Line Items]
Indefinite-lived intangible assets (excluding goodwill)	51,021	51,021
Customer-related
Finite Lived And Indefinite Lived Intangible Assets By Major Class [Line Items]
Amortizable intangible assets, gross carrying amount	392,963	391,135
Amortizable intangible assets, accumulated amortization	(340,134)	(332,841)
Amortizable intangible assets, net	52,829	58,294
Non-compete agreements
Finite Lived And Indefinite Lived Intangible Assets By Major Class [Line Items]
Amortizable intangible assets, gross carrying amount	29,284	28,894
Amortizable intangible assets, accumulated amortization	(26,683)	(26,054)
Amortizable intangible assets, net	$ 2,601	$ 2,840