Supplemental financial statement information - Shipping and Handling (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2022	Oct. 31, 2021
Supplemental Financial Statement Information [Line Items]
Operating expense - personnel, vehicle, plant and other	$ 129,740	$ 117,112
Depreciation and amortization expense	22,631	20,295
Operating expense - equipment lease expense	6,024	5,690
Shipping and Handling
Supplemental Financial Statement Information [Line Items]
Operating expense - personnel, vehicle, plant and other	64,172	54,447
Depreciation and amortization expense	3,837	2,535
Operating expense - equipment lease expense	3,754	4,535
Costs and Expenses, Total	$ 71,763	$ 61,517