Revenue from contracts with customers (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2022	Apr. 30, 2021	Jul. 31, 2021
Disaggregation of Revenue [Line Items]
Revenues	$ 647,543	$ 564,730	$ 1,726,987	$ 1,419,184
Contract assets and liabilities
Accounts receivable	204,728		204,728		$ 138,757
Contract assets	21,257		21,257		10,074
Contract liabilities
Deferred revenue	$ 43,061		43,061		49,354
Deferred revenue recognized			$ 8,600
Maximum [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-11-01
Contract liabilities
Remaining performance obligation recognition period	1 year		1 year
Propane And Related Equipment [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 647,543	564,730	$ 1,726,987	1,419,184
Retail Sales To End Users [Member]
Disaggregation of Revenue [Line Items]
Revenues	478,807	392,838	1,228,062	945,833
Wholesale Sales To Resellers [Member]
Disaggregation of Revenue [Line Items]
Revenues	137,148	140,015	405,713	381,357
Other Gas Sales [Member]
Disaggregation of Revenue [Line Items]
Revenues	6,256	9,183	18,644	24,329
Other Revenues
Disaggregation of Revenue [Line Items]
Revenues	25,332	22,694	74,568	67,665
Ferrellgas, L.P. [Member]
Disaggregation of Revenue [Line Items]
Revenues	647,543	564,730	1,726,985	1,419,184
Contract assets and liabilities
Accounts receivable	204,728		204,728		138,757
Contract assets	21,257		21,257		10,074
Contract liabilities
Deferred revenue	$ 43,061		43,061		$ 49,354
Deferred revenue recognized			$ 8,600
Ferrellgas, L.P. [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-05-01
Contract liabilities
Remaining performance obligation recognition period	1 year		1 year
Ferrellgas, L.P. [Member] | Propane And Related Equipment [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 647,543	564,730	$ 1,726,985	1,419,184
Ferrellgas, L.P. [Member] | Retail Sales To End Users [Member]
Disaggregation of Revenue [Line Items]
Revenues	478,807	392,838	1,228,062	945,833
Ferrellgas, L.P. [Member] | Wholesale Sales To Resellers [Member]
Disaggregation of Revenue [Line Items]
Revenues	137,148	140,015	405,713	381,357
Ferrellgas, L.P. [Member] | Other Gas Sales [Member]
Disaggregation of Revenue [Line Items]
Revenues	6,256	9,183	18,644	24,329
Ferrellgas, L.P. [Member] | Other Revenues
Disaggregation of Revenue [Line Items]
Revenues	$ 25,332	$ 22,694	$ 74,566	$ 67,665