Derivative Instruments and Hedging Activities (Fair Value Hedge Derivative Effect on Earnings) (Details) - Interest Rate Swap [Member] - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Derivative, Gain (Loss) on Derivative, Net	$ 1,319	$ 1,919	$ 1,892
Interest Expense, Debt	(9,100)	(9,100)	(9,100)
Ferrellgas, L.P. [Member]
Derivative, Gain (Loss) on Derivative, Net	1,319	1,919	1,892
Interest Expense, Debt	$ (9,100)	$ (9,100)	$ (9,100)