Revenue from contracts with customers (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2023	Jan. 31, 2022	Jan. 31, 2023	Jan. 31, 2022	Jul. 31, 2022
Disaggregation of Revenue [Line Items]
Revenues	$ 683,943	$ 684,938	$ 1,097,232	$ 1,079,444
Contract assets and liabilities
Contract assets	15,861		15,861		$ 11,935
Contract liabilities
Deferred revenue	$ 50,062		50,062		$ 47,929
Deferred revenue recognized			$ 28,600
Maximum | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-11-01
Contract liabilities
Remaining performance obligation recognition period	1 year		1 year
Propane And Related Equipment
Disaggregation of Revenue [Line Items]
Revenues	$ 683,943	684,938	$ 1,097,232	1,079,444
Retail Sales To End Users
Disaggregation of Revenue [Line Items]
Revenues	498,449	496,745	764,423	749,255
Wholesale Sales To Resellers
Disaggregation of Revenue [Line Items]
Revenues	148,608	154,594	264,622	268,565
Other Gas Sales
Disaggregation of Revenue [Line Items]
Revenues	4,829	6,165	8,685	12,388
Other Revenues
Disaggregation of Revenue [Line Items]
Revenues	32,057	27,434	59,502	49,236
Ferrellgas, L.P
Disaggregation of Revenue [Line Items]
Revenues	683,943	684,936	1,097,232	1,079,442
Ferrellgas, L.P | Propane And Related Equipment
Disaggregation of Revenue [Line Items]
Revenues	683,943	684,936	1,097,232	1,079,442
Ferrellgas, L.P | Retail Sales To End Users
Disaggregation of Revenue [Line Items]
Revenues	498,449	496,745	764,423	749,255
Ferrellgas, L.P | Wholesale Sales To Resellers
Disaggregation of Revenue [Line Items]
Revenues	148,608	154,594	264,622	268,565
Ferrellgas, L.P | Other Gas Sales
Disaggregation of Revenue [Line Items]
Revenues	4,829	6,165	8,685	12,388
Ferrellgas, L.P | Other Revenues
Disaggregation of Revenue [Line Items]
Revenues	$ 32,057	$ 27,432	$ 59,502	$ 49,234