Derivative Instruments and Hedging Activities (Changes in Derivative Value Effect on Other Comprehensive Income Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Jul. 31, 2016	Jul. 31, 2015
Beginning balance	$ (1,186)		$ (10,468)
Change in value of risk management derivatives	5,138	$ 384
Reclassification of gains and losses on commodity hedges to cost of product sold - propane and other gas liquids sales	4,238	8,226
Ending balance	(1,186)
Ferrellgas, L.P. [Member]
Beginning balance	(1,184)		(10,560)
Change in value of risk management derivatives	5,138	384
Reclassification of gains and losses on commodity hedges to cost of product sold - propane and other gas liquids sales	4,238	8,226
Ending balance	(1,184)
Propane commodity derivatives [Member]
Change in value of risk management derivatives	4,873	1,585
Reclassification of gains and losses on commodity hedges to cost of product sold - propane and other gas liquids sales	3,596	7,449
Propane commodity derivatives [Member] | Ferrellgas, L.P. [Member]
Change in value of risk management derivatives	4,873	1,585
Reclassification of gains and losses on commodity hedges to cost of product sold - propane and other gas liquids sales	3,596	7,449
Interest Rate Swap [Member]
Change in value of risk management derivatives	265	(1,201)
Derivative, Net Hedge Ineffectiveness Gain (Loss)	642	777
Interest Rate Swap [Member] | Ferrellgas, L.P. [Member]
Change in value of risk management derivatives	265	(1,201)
Derivative, Net Hedge Ineffectiveness Gain (Loss)	642	777
Derivative [Member]
Beginning balance	(439)	(30,296)	(9,815)	$ (38,906)
Ending balance	(439)	(30,296)
Derivative [Member] | Ferrellgas, L.P. [Member]
Beginning balance	(439)	(30,296)	$ (9,815)	$ (38,906)
Ending balance	$ (439)	$ (30,296)