Supplemental financial statement information - Shipping and Handling (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2022	Jul. 31, 2021	Jul. 31, 2020
Supplemental Financial Statement Information [Line Items]
Operating expense - personnel, vehicle, plant and other	$ 520,603	$ 465,816	$ 493,055
Depreciation and amortization expense	89,897	85,382	80,481
Operating expense - equipment lease expense	23,094	27,062	33,017
Shipping and Handling [Member]
Supplemental Financial Statement Information [Line Items]
Operating expense - personnel, vehicle, plant and other	244,022	217,292	219,598
Depreciation and amortization expense	14,370	13,691	9,857
Operating expense - equipment lease expense	18,874	22,609	32,518
Costs and Expenses, Total	277,266	253,592	261,973
Ferrellgas, L.P. [Member]
Supplemental Financial Statement Information [Line Items]
Operating expense - personnel, vehicle, plant and other	520,603	465,816	493,055
Depreciation and amortization expense	89,897	85,382	80,481
Operating expense - equipment lease expense	$ 23,094	$ 27,062	$ 33,017