Fair Value Measurements - Assets and Liabilities (Details) - USD ($) $ in Thousands	Jul. 31, 2022	Jul. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivatives propane swap assets	$ 51,267	$ 94,244
Commodity derivatives propane swap liabilities	(12,960)	(4,458)
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivatives propane swap assets	0	0
Commodity derivatives propane swap liabilities	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivatives propane swap assets	51,267	94,244
Commodity derivatives propane swap liabilities	(12,960)	(4,458)
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivatives propane swap assets	0	0
Commodity derivatives propane swap liabilities	$ 0	$ 0