Partners' Deficit - Paid Distributions (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2019	Oct. 31, 2018
Limited Partners' Capital Account [Line Items]
Distributions paid	$ 1	$ 9,915
Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid	101	10,015
Ferrellgas Inc., General Partner [Member] | Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid	1	101
Ferrellgas Partners LP [Member] | Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid	100	9,914
Parent [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		9,814
Parent [Member] | Ferrell Companies [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		2,253
Parent [Member] | FCI Trading Corp. [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		20
Parent [Member] | Ferrell Propane, Inc. [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		5
Parent [Member] | James E. Ferrell [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		476
Parent [Member] | Ferrellgas Inc., General Partner [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		98
Common Unitholders [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		9,716
Common Unitholders [Member] | Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid	100	9,914
Public Common Unitholders [Member] | Parent [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		6,962
General Partner [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		98
General Partner [Member] | Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid	$ 1	$ 101