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Derivative instruments and hedging activities - Balance Sheet (Details) - USD ($) $ in Thousands	9 Months Ended
	Apr. 30, 2024	Apr. 30, 2023	Jul. 31, 2023
Derivative instruments and hedging activities
Gain (loss) recognized due to ineffectiveness	$ 0	$ 0
Derivative Asset, Fair Value, Gross Asset	5,631		$ 12,165
Derivative Liability, Fair Value, Gross Liability	4,589		11,082
Price risk management asset
Derivative instruments and hedging activities
Commodity derivatives propane swap assets	5,398		11,966
Other Current Liabilities
Derivative instruments and hedging activities
Commodity derivatives propane swap liabilities	4,166		9,554
Other Assets, Net
Derivative instruments and hedging activities
Commodity derivatives propane swap assets	233		199
Other Liabilities
Derivative instruments and hedging activities
Commodity derivatives propane swap liabilities	$ 423		$ 1,528