Fair value measurements - Assets and Liabilities (Details) - Fair Value, Recurring - USD ($) $ in Thousands	Jul. 31, 2025	Jul. 31, 2024
Fair value measurements
Commodity derivatives propane swap assets	$ 3,570	$ 6,519
Commodity derivatives propane swap liabilities	(3,654)	(4,460)
Level 1
Fair value measurements
Commodity derivatives propane swap assets	0	0
Commodity derivatives propane swap liabilities	0	0
Level 2
Fair value measurements
Commodity derivatives propane swap assets	3,570	6,519
Commodity derivatives propane swap liabilities	(3,654)	(4,460)
Level 3
Fair value measurements
Commodity derivatives propane swap assets	0	0
Commodity derivatives propane swap liabilities	$ 0	$ 0

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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