Partners' Capital (Limited Partner Units) (Details) - shares	Jul. 31, 2017	Jul. 31, 2016
Capital Unit [Line Items]
Common unitholders, units outstanding	97,152,665	98,002,665
Public Common Unitholders [Member]
Capital Unit [Line Items]
Common unitholders, units outstanding	69,612,939	70,462,939
Ferrell Companies [Member]
Capital Unit [Line Items]
Common unitholders, units outstanding	22,529,361	22,529,361
FCI Trading Corp. [Member]
Capital Unit [Line Items]
Common unitholders, units outstanding	195,686	195,686
Ferrell Propane, Inc. [Member]
Capital Unit [Line Items]
Common unitholders, units outstanding	51,204	51,204
James E. Ferrell [Member]
Capital Unit [Line Items]
Common unitholders, units outstanding	4,763,475	4,763,475