Partners' Capital (Distributions Paid) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2018	Apr. 30, 2017	Apr. 30, 2018	Apr. 30, 2017
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	$ 9,813	$ 9,813	$ 29,440	$ 69,920
Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	10,115	9,913	45,495	94,413
Public Common Unitholders [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	6,961	6,961	20,884	49,600
Ferrell Companies [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	2,253	2,253	6,759	16,052
FCI Trading Corp. [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	20	20	60	140
Ferrell Propane, Inc [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	5	5	15	36
James E. Ferrell [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	476	476	1,428	3,393
Ferrellgas Partners [Member] | Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	10,013	9,813	45,036	93,620
General Partner [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	98	98	294	699
General Partner [Member] | Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	$ 102	$ 100	$ 459	$ 793