Derivative Instruments and Hedging Activities - Effect on Comprehensive Income and Change in FV (Details) - Commodity Derivatives Propane [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2022	Apr. 30, 2021	Apr. 30, 2022	Apr. 30, 2021
Derivative [Line Items]
Amount of gain (loss) recognized in AOCI on derivative	$ 29,355	$ 20,446	$ 84,427	$ 63,170
Cost of Sales [Member]
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into income	44,145	22,383	96,965	28,674
Ferrellgas, L.P. [Member] | Cost of Sales [Member]
Derivative [Line Items]
Amount of gain (loss) recognized in AOCI on derivative	29,355	20,446	84,427	63,170
Amount of gain (loss) reclassified from AOCI into income	$ 44,145	$ 22,383	$ 96,965	$ 28,674