Supplemental Financial Statement Information - Other Current Liabilities (Details) - USD ($) $ in Thousands	Jul. 31, 2019	Jul. 31, 2018
Supplemental Financial Statement Information [Line Items]
Customer deposits and advances	$ 24,686	$ 22,829
Accrued interest	20,484	22,222
Accrued payroll	17,356	16,060
Accrued insurance	18,524	15,100
Price risk management liabilities	14,198	1,832
Other	42,989	61,580
Other current liabilities	138,237	139,623
Ferrellgas, L.P. [Member]
Supplemental Financial Statement Information [Line Items]
Customer deposits and advances	16,550	18,288
Accrued interest	24,686	22,829
Accrued payroll	17,356	16,060
Accrued insurance	18,524	15,100
Price risk management liabilities	14,198	1,832
Other	42,989	61,580
Other current liabilities	$ 134,303	$ 135,689