Partners' Deficit - Paid Distributions (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2019	Jan. 31, 2018	Jan. 31, 2019	Jan. 31, 2018
Limited Partners' Capital Account [Line Items]
Distributions paid		$ 9,814	$ 10,072
Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid	$ 15,553	25,467	25,568	$ 35,380
Ferrell Companies [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		2,253
FCI Trading Corp. [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		20
Ferrell Propane, Inc. [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		5
James E. Ferrell [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		476
Ferrellgas Inc., General Partner [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		98
Ferrellgas Inc., General Partner [Member] | Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid	157	257	258	357
Ferrellgas Partners LP [Member] | Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid	$ 15,396	25,210	25,310	35,023
Parent [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid			9,814	19,627
Parent [Member] | Ferrell Companies [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid			2,253	4,506
Parent [Member] | FCI Trading Corp. [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid			20	40
Parent [Member] | Ferrell Propane, Inc. [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid			5	10
Parent [Member] | James E. Ferrell [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid			476	952
Parent [Member] | Ferrellgas Inc., General Partner [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid			98	196
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			25,310
Public Common Unitholders [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid		$ 6,962
Public Common Unitholders [Member] | Parent [Member]
Limited Partners' Capital Account [Line Items]
Distributions paid			$ 6,962	$ 13,923