Supplemental Financial Statement Information - Other Current Liabilities (Details) - USD ($) $ in Thousands	Jan. 31, 2020	Jul. 31, 2019
Supplemental Financial Statement Information [Line Items]
Accrued interest	$ 22,503	$ 20,484
Customer deposits and advances	27,286	24,686
Accrued payroll	22,947	17,356
Accrued insurance	13,684	18,524
Price risk management liabilities	22,861	14,198
Other	46,059	42,989
Other current liabilities	155,340	138,237
Ferrellgas, L.P. [Member]
Supplemental Financial Statement Information [Line Items]
Accrued interest	18,569	16,550
Customer deposits and advances	27,286	24,686
Accrued payroll	22,947	17,356
Accrued insurance	13,684	18,524
Price risk management liabilities	22,861	14,198
Other	46,059	42,989
Other current liabilities	$ 151,406	$ 134,303