Derivative Instruments and Hedging Activities - Effect on Earnings (Details) - USD ($) $ in Thousands		12 Months Ended
	May 03, 2018	Jul. 31, 2018	Jul. 31, 2017
Derivative [Line Items]
Swap Termination Payment	$ 4,200	$ 4,200
Ferrellgas, L.P. [Member]
Derivative [Line Items]
Swap Termination Payment	$ 4,200	4,200
Interest Rate Swap [Member]
Derivative [Line Items]
Amount of Gain Recognized		266	$ 1,319
Amount of Interest Expense Recognized		(6,825)	(9,100)
Interest Rate Swap [Member] | Ferrellgas, L.P. [Member]
Derivative [Line Items]
Amount of Gain Recognized		266	1,319
Amount of Interest Expense Recognized		$ (6,825)	$ (9,100)