Partners' Capital (Distributions Paid) (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2017	Oct. 31, 2016
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	$ 9,813	$ 50,294
Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	9,913	66,658
Public Common Unitholders [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	6,961	35,678
Ferrell Companies [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	2,253	11,546
FCI Trading Corp. [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	20	100
Ferrell Propane, Inc [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	5	26
James E. Ferrell [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	476	2,441
Ferrellgas Partners [Member] | Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	9,813	66,145
General Partner [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	98	503
General Partner [Member] | Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	$ 100	$ 513