Summary of significant accounting policies - Deferred Taxes Assets And Liabilities (Details) - USD ($) $ in Thousands	Jul. 31, 2022	Jul. 31, 2021
Significant Accounting Policies [Line Items]
Deferred tax assets (included in Other assets, net)	$ 4	$ 5
Deferred tax liabilities (included in Other liabilities)	(9)	(3)
Net deferred tax asset		2
Net deferred tax liability	(5)
Ferrellgas, L.P. [Member]
Significant Accounting Policies [Line Items]
Deferred tax assets (included in Other assets, net)	4	5
Deferred tax liabilities (included in Other liabilities)	(9)	(3)
Net deferred tax asset		$ 2
Net deferred tax liability	$ (5)