Derivative Instruments and Hedging Activities Derivative Instruments and Hedging Activities (Derivatives not Designated as Hedging Instruments Effects on Earnings) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Cost of Sales [Member] | Midstream - Crude Oil Logistics [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ (425)	$ 1,084
Cost of Sales [Member] | Midstream - Crude Oil Logistics [Member] | Ferrellgas, L.P. [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(425)	1,084
Operating Expense [Member] | Propane and related equipment sales [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	1,090	(4,351)	$ (2,412)
Operating Expense [Member] | Propane and related equipment sales [Member] | Ferrellgas, L.P. [Member]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 1,090	$ (4,351)	$ (2,412)