Partners' Capital (Distributions Paid) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	$ 9,814	$ 9,813	$ 19,627	$ 60,107
Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	25,467	17,842	35,380	84,500
Public Common Unitholders [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	6,962	6,961	13,923	42,639
Ferrell Companies [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	2,253	2,253	4,506	13,799
FCI Trading Corp. [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	20	20	40	120
Ferrell Propane, Inc [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	5	5	10	31
James E. Ferrell [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	476	476	952	2,917
Ferrellgas Partners [Member] | Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	25,210	17,662	35,023	83,807
General Partner [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	98	98	196	601
General Partner [Member] | Ferrellgas, L.P. [Member]
Limited Partners' Capital Account [Line Items]
Distribution Made to Limited Partner, Cash Distributions Paid	$ 257	$ 180	$ 357	$ 693