Fair Value Measurements (Assets And Liabilities Fair Value Hierarchy) (Details) - USD ($) $ in Thousands	Apr. 30, 2018	Jul. 31, 2017
Interest rate swap assets	$ 41	$ 583
Propane commodity derivative assets	19,750	16,212
Interest rate swap liabilities	(3,222)	(707)
Propane commodity derivative liabilities	(2,239)	(1,258)
Ferrellgas, L.P. [Member]
Interest rate swap assets	41	583
Propane commodity derivative assets	19,750	16,212
Interest rate swap liabilities	(3,222)	(707)
Propane commodity derivative liabilities	(2,239)	(1,258)
Fair Value, Inputs, Level 1 [Member]
Interest rate swap assets	0	0
Propane commodity derivative assets	0	0
Interest rate swap liabilities	0	0
Propane commodity derivative liabilities	0	0
Fair Value, Inputs, Level 1 [Member] \| Ferrellgas, L.P. [Member]
Interest rate swap assets	0	0
Propane commodity derivative assets	0	0
Interest rate swap liabilities	0	0
Propane commodity derivative liabilities	0	0
Fair Value, Inputs, Level 2 [Member]
Interest rate swap assets	41	583
Propane commodity derivative assets	19,750	16,212
Interest rate swap liabilities	(3,222)	(707)
Propane commodity derivative liabilities	(2,239)	(1,258)
Fair Value, Inputs, Level 2 [Member] \| Ferrellgas, L.P. [Member]
Interest rate swap assets	41	583
Propane commodity derivative assets	19,750	16,212
Interest rate swap liabilities	(3,222)	(707)
Propane commodity derivative liabilities	(2,239)	(1,258)
Fair Value, Inputs, Level 3 [Member]
Interest rate swap assets	0	0
Propane commodity derivative assets	0	0
Interest rate swap liabilities	0	0
Propane commodity derivative liabilities	0	0
Fair Value, Inputs, Level 3 [Member] \| Ferrellgas, L.P. [Member]
Interest rate swap assets	0	0
Propane commodity derivative assets	0	0
Interest rate swap liabilities	0	0
Propane commodity derivative liabilities	$ 0	$ 0

Fair value as of the balance sheet date of interest rate derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611

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