Net (loss) earnings per unitholders' interest (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2024	Apr. 30, 2023	Apr. 30, 2024	Apr. 30, 2023
Earnings Distribution Allocation [Line Items]
Net earnings attributable to Ferrellgas Partners, L.P.	$ 52,766	$ 72,427	$ 130,999	$ 165,982
Less: Allocation of undistributed net earnings to Class B units				49,653
Less: General partner's interest in net earnings (loss)	527	724	1,310	1,660
Undistributed net (loss) earnings attributable to Class A unitholders	(63,802)	6,115	$ (18,853)	16,608
Allocation of earnings to Class B units relative to allocation to Class A units			6
Preferred Units
Earnings Distribution Allocation [Line Items]
Less: Distributions to preferred unitholders	$ 16,045	$ 15,590	$ 48,546	$ 48,063
Class A Limited Partner Units
Earnings Distribution Allocation [Line Items]
Weighted average Class A Units outstanding (in thousands)	4,857,600	4,857,600	4,857,600	4,857,600
Basic and diluted net (loss) earnings per Class A Unit	$ (13.13)	$ 1.26	$ (3.88)	$ 3.42
Class B Limited Partner Units
Earnings Distribution Allocation [Line Items]
Less: Distributions to preferred unitholders	$ 99,996	$ 49,998	$ 99,996	$ 49,998
Percentage of allocated earnings			100.00%