Revenue from contracts with customers (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2022	Oct. 31, 2021	Jul. 31, 2022
Disaggregation of Revenue [Line Items]
Revenues	$ 413,289	$ 394,506
Contract assets and liabilities
Contract assets	6,833		$ 11,935
Contract liabilities
Deferred revenue	57,423		$ 47,929
Deferred revenue recognized	$ 14,500
Maximum | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-11-01
Contract liabilities
Remaining performance obligation recognition period	1 year
Propane And Related Equipment
Disaggregation of Revenue [Line Items]
Revenues	$ 413,289	394,506
Retail Sales To End Users
Disaggregation of Revenue [Line Items]
Revenues	265,974	252,510
Wholesale Sales To Resellers
Disaggregation of Revenue [Line Items]
Revenues	116,014	113,971
Other Gas Sales
Disaggregation of Revenue [Line Items]
Revenues	3,856	6,223
Other Revenues
Disaggregation of Revenue [Line Items]
Revenues	$ 27,445	$ 21,802