Derivative Instruments and Hedging Activities (Fair Value Hedge Derivative Effect on Earnings) (Details) - Interest Rate Swap [Member] - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2016	Oct. 31, 2015
Derivative, Gain (Loss) on Derivative, Net	$ 420	$ 537
Interest expense recognized on fixed-rate debt	(2,275)	(2,275)
Ferrellgas, L.P. [Member]
Derivative, Gain (Loss) on Derivative, Net	420	537
Interest expense recognized on fixed-rate debt	$ (2,275)	$ (2,275)