Fair Value Measurements - Assets and Liabilities (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Apr. 30, 2022	Jul. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivatives propane swap assets	$ 91,724	$ 94,244
Commodity derivatives propane swap liabilities	(14,476)	(4,458)
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivatives propane swap assets	91,724	94,244
Commodity derivatives propane swap liabilities	(14,476)	(4,458)
Ferrellgas, L.P. [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivatives propane swap assets	91,724	94,244
Commodity derivatives propane swap liabilities	(14,476)	(4,458)
Ferrellgas, L.P. [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivatives propane swap assets	91,724	94,244
Commodity derivatives propane swap liabilities	$ (14,476)	$ (4,458)