Derivative Instruments and Hedging Activities (Fair Value Hedge Derivative Effect on Earnings) (Details) - Interest Rate Swap [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Derivative, Gain (Loss) on Derivative, Net	$ 88	$ 328	$ 226	$ 748
Interest expense recognized on fixed-rate debt	(2,275)	(2,275)	4,550	4,550
Ferrellgas, L.P. [Member]
Derivative, Gain (Loss) on Derivative, Net	88	328	226	748
Interest expense recognized on fixed-rate debt	$ (2,275)	$ (2,275)	$ 4,550	$ 4,550