Supplemental Financial Statement Information (Property, Plant And Equipment) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Property, Plant and Equipment [Line Items]
Asset Impairment Charges	$ 628,800,000	$ 0	$ 658,118,000	$ 0
Property, plant and equipment, gross	1,415,033,000	1,393,457,000	1,415,033,000
Less: accumulated depreciation	640,353,000	661,534,000	640,353,000
Property, plant and equipment, net	774,680,000	731,923,000	774,680,000
Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Asset Impairment Charges	628,800,000	0	658,118,000	$ 0
Property, plant and equipment, gross	1,415,033,000	1,393,457,000	1,415,033,000
Less: accumulated depreciation	640,353,000	661,534,000	640,353,000
Property, plant and equipment, net	774,680,000	$ 731,923,000	774,680,000
Land [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		Indefinite
Property, plant and equipment, gross	35,309,000	$ 35,824,000	35,309,000
Land [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		Indefinite
Property, plant and equipment, gross	35,309,000	$ 35,824,000	35,309,000
Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	14,097,000	14,342,000	14,097,000
Land Improvements [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	14,097,000	$ 14,342,000	14,097,000
Buildings And Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		20 years
Property, plant and equipment, gross	73,021,000	$ 73,333,000	73,021,000
Buildings And Improvements [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		20 years
Property, plant and equipment, gross	73,021,000	$ 73,333,000	73,021,000
Vehicles, Including Transport Trailers [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	122,691,000	121,233,000	122,691,000
Vehicles, Including Transport Trailers [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	122,691,000	121,233,000	122,691,000
Bulk Equipment And District Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	104,428,000	104,291,000	104,428,000
Bulk Equipment And District Facilities [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	104,428,000	104,291,000	104,428,000
Tanks, Cylinders And Customer Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	767,234,000	755,867,000	767,234,000
Tanks, Cylinders And Customer Equipment [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	767,234,000	755,867,000	767,234,000
Salt water disposal wells [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	57,695,000	52,495,000	57,695,000
Salt water disposal wells [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	57,695,000	$ 52,495,000	57,695,000
Rail cars [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		30 years
Property, plant and equipment, gross	92,980,000	$ 91,787,000	92,980,000
Rail cars [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		30 years
Property, plant and equipment, gross	92,980,000	$ 91,787,000	92,980,000
Computer And Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	122,304,000	118,518,000	122,304,000
Computer And Office Equipment [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	122,304,000	$ 118,518,000	122,304,000
Injection stations [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		20 years
Property, plant and equipment, gross	13,130,000	$ 13,130,000	13,130,000
Injection stations [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		20 years
Property, plant and equipment, gross	13,130,000	$ 13,130,000	13,130,000
Construction In Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	10,481,000	10,974,000	10,481,000
Construction In Progress [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	10,481,000	$ 10,974,000	10,481,000
Pipelines [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		15 years
Property, plant and equipment, gross	1,663,000	$ 1,663,000	1,663,000
Pipelines [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		15 years
Property, plant and equipment, gross	$ 1,663,000	$ 1,663,000	1,663,000
Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		2 years
Minimum [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		2 years
Minimum [Member] | Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		2 years
Minimum [Member] | Land Improvements [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		2 years
Minimum [Member] | Vehicles, Including Transport Trailers [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		8 years
Minimum [Member] | Vehicles, Including Transport Trailers [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		8 years
Minimum [Member] | Bulk Equipment And District Facilities [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		5 years
Minimum [Member] | Bulk Equipment And District Facilities [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		5 years
Minimum [Member] | Tanks, Cylinders And Customer Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		2 years
Minimum [Member] | Tanks, Cylinders And Customer Equipment [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		2 years
Minimum [Member] | Salt water disposal wells [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		2 years
Minimum [Member] | Salt water disposal wells [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		2 years
Minimum [Member] | Computer And Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		2 years
Minimum [Member] | Computer And Office Equipment [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		2 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		30 years
Maximum [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		30 years
Maximum [Member] | Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		20 years
Maximum [Member] | Land Improvements [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		20 years
Maximum [Member] | Vehicles, Including Transport Trailers [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		20 years
Maximum [Member] | Vehicles, Including Transport Trailers [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		20 years
Maximum [Member] | Bulk Equipment And District Facilities [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		30 years
Maximum [Member] | Bulk Equipment And District Facilities [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		30 years
Maximum [Member] | Tanks, Cylinders And Customer Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		30 years
Maximum [Member] | Tanks, Cylinders And Customer Equipment [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		30 years
Maximum [Member] | Salt water disposal wells [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		30 years
Maximum [Member] | Salt water disposal wells [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		30 years
Maximum [Member] | Computer And Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		5 years
Maximum [Member] | Computer And Office Equipment [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives		5 years
Property And Equipment [Member]
Property, Plant and Equipment [Line Items]
Asset Impairment Charges			181,800,000
Property And Equipment [Member] | Ferrellgas, L.P. [Member]
Property, Plant and Equipment [Line Items]
Asset Impairment Charges			$ 181,800,000