Derivative instruments and hedging activities - Effect on Comprehensive Income and Change in FV (Details) - Commodity Derivatives Propane - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2024	Apr. 30, 2023	Apr. 30, 2024	Apr. 30, 2023
Derivative instruments and hedging activities
Amount of gain (loss) recognized in AOCI on derivative	$ (1,180)	$ (10,621)	$ (116)	$ (53,044)
Cost of Sales
Derivative instruments and hedging activities
Amount of gain (loss) reclassified from AOCI into income	$ 5,179	$ (13,450)	$ (75)	$ (7,378)