Supplemental Information - Other Current Liabilities (Details) - USD ($) $ in Thousands	Jan. 31, 2021	Jul. 31, 2020
Supplemental Financial Statement Information [Line Items]
Accrued interest	$ 34,583	$ 53,841
Customer deposits and advances	33,144	32,257
Accrued payroll	23,902	18,375
Accrued insurance	11,416	14,796
Other	88,863	48,197
Other current liabilities	191,908	167,466
Ferrellgas, L.P. [Member]
Supplemental Financial Statement Information [Line Items]
Accrued interest	34,583	34,511
Customer deposits and advances	33,144	32,257
Accrued payroll	23,902	18,375
Accrued insurance	11,416	14,796
Other	87,663	48,197
Other current liabilities	$ 190,708	$ 148,136