The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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Derivative Instruments and Hedging Activities - Effect on Comprehensive Income and Change in FV (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2019	Jan. 31, 2018
Derivative [Line Items]
Amount of gain (loss) recognized in AOCI(L) on derivative	$ (21,080)	$ 1,072	$ (29,234)	$ 23,521
Amount of gain (loss) reclassified from AOCI into income	3,807	9,743	(626)	13,692
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0	314	0	(1,293)
Ferrellgas, L.P. [Member]
Derivative [Line Items]
Amount of gain (loss) recognized in AOCI(L) on derivative	(21,080)	1,072	(29,234)	23,521
Amount of gain (loss) reclassified from AOCI into income	3,807	9,743	(626)	13,692
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		314	0	(1,293)
Commodity Derivatives Propane [Member]
Derivative [Line Items]
Amount of gain (loss) recognized in AOCI(L) on derivative	(21,080)	960	(29,234)	23,283
Commodity Derivatives Propane [Member] \| Ferrellgas, L.P. [Member]
Derivative [Line Items]
Amount of gain (loss) recognized in AOCI(L) on derivative	(21,080)	960	(29,234)	23,283
Interest Rate Swap [Member]
Derivative [Line Items]
Amount of gain (loss) recognized in AOCI(L) on derivative		112		238
Interest Rate Swap [Member] \| Ferrellgas, L.P. [Member]
Derivative [Line Items]
Amount of gain (loss) recognized in AOCI(L) on derivative		112		238
Interest Expense [Member] \| Interest Rate Swap [Member]
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into income		(143)		(326)
Interest Expense [Member] \| Interest Rate Swap [Member] \| Ferrellgas, L.P. [Member]
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into income		(143)		(326)
Midstream Operations [Member] \| Cost of Sales [Member] \| Ferrellgas, L.P. [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		(2,080)
Midstream Operations [Member] \| Operating Expense [Member] \| Commodity Derivatives Crude Oil [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net		(2,080)		(3,470)
Midstream Operations [Member] \| Operating Expense [Member] \| Commodity Derivatives Crude Oil [Member] \| Ferrellgas, L.P. [Member]
Derivative [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net				(3,470)
Propane [Member] \| Cost of Sales [Member] \| Commodity Derivatives Propane [Member]
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into income	3,807	9,886	(626)	14,018
Propane [Member] \| Cost of Sales [Member] \| Commodity Derivatives Propane [Member] \| Ferrellgas, L.P. [Member]
Derivative [Line Items]
Amount of gain (loss) reclassified from AOCI into income	$ 3,807	$ 9,886	$ (626)	$ 14,018