Supplemental financial statement information - Cash, Cash Equivalents And Restricted Cash (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2022	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2019
Supplemental Financial Statement Information [Line Items]
Cash and cash equivalents	$ 147,529	$ 270,452
Restricted cash	11,208	11,500
Cash deposit against contingencies	11,200	11,500
Cash, cash equivalents and restricted cash	158,737	281,952	$ 333,761	$ 11,054
Cash paid for interest	91,897	156,449	147,402
Income taxes	1,018	706	289
Noncash Investing and Financing Items [Abstract]
Liability incurred in connection with Financing Agreement amendment			8,863
Liabilities incurred in connection with acquisitions	2,022	1,344	975
Change in accruals for property, plant and equipment additions	450	(386)	216
Lease liabilities arising from operating right-of-use assets	12,748	8,374	14,938
Lease liabilities arising from finance right-of-use assets	2,209	2,310	45,455
Accrued senior preferred units distributions	17,466	16,013
Ferrellgas, L.P. [Member]
Supplemental Financial Statement Information [Line Items]
Cash and cash equivalents	147,258	270,188
Restricted cash	11,208	11,500
Cash deposit against contingencies	11,200	11,500
Cash, cash equivalents and restricted cash	158,466	281,688	333,755	$ 11,046
Cash paid for interest	91,897	156,449	132,006
Income taxes	1,014	693	241
Noncash Investing and Financing Items [Abstract]
Liability incurred in connection with Financing Agreement amendment			8,863
Liabilities incurred in connection with acquisitions	2,022	1,344	975
Change in accruals for property, plant and equipment additions	450	(386)	216
Lease liabilities arising from operating right-of-use assets	12,748	8,374	14,938
Lease liabilities arising from finance right-of-use assets	2,209	2,310	$ 45,455
Accrued senior preferred units distributions	$ 17,466	$ 16,013