Supplemental financial statement information - Shipping and Handling (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2023	Oct. 31, 2022
Supplemental Financial Statement Information [Line Items]
Operating expense - personnel, vehicle, plant and other	$ 144,646	$ 129,740
Depreciation and amortization expense	24,404	22,631
Operating expense - equipment lease expense	5,376	6,024
Shipping and Handling
Supplemental Financial Statement Information [Line Items]
Operating expense - personnel, vehicle, plant and other	73,969	64,172
Depreciation and amortization expense	3,366	3,837
Operating expense - equipment lease expense	3,436	3,754
Shipping and handling expenses	$ 80,771	$ 71,763