Derivative Instruments and Hedging Activities - Derivative Collateral (Details) - USD ($) $ in Thousands	Jan. 31, 2019	Jul. 31, 2018
Derivative [Line Items]
Derivative Asset, Fair Value of Collateral	$ 13,594	$ 3,778
Derivative Liability, Fair Value of Collateral	1,737	16,543
Prepaid Expenses and Other Current Assets [Member]
Derivative [Line Items]
Derivative Asset, Fair Value of Collateral	10,977	2,851
Other Current Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value of Collateral	1,734	12,308
Other Assets, Net [Member]
Derivative [Line Items]
Derivative Asset, Fair Value of Collateral	2,617	927
Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value of Collateral	3	4,235
Ferrellgas, L.P. [Member]
Derivative [Line Items]
Derivative Asset, Fair Value of Collateral	13,594	3,778
Derivative Liability, Fair Value of Collateral	1,737	16,543
Ferrellgas, L.P. [Member] \| Prepaid Expenses and Other Current Assets [Member]
Derivative [Line Items]
Derivative Asset, Fair Value of Collateral	10,977	2,851
Ferrellgas, L.P. [Member] \| Other Current Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value of Collateral	1,734	12,308
Ferrellgas, L.P. [Member] \| Other Assets, Net [Member]
Derivative [Line Items]
Derivative Asset, Fair Value of Collateral	2,617	927
Ferrellgas, L.P. [Member] \| Other Liabilities [Member]
Derivative [Line Items]
Derivative Liability, Fair Value of Collateral	$ 3	$ 4,235

Fair value of securities received as collateral against derivative assets.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226013-175313

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Fair value of securities pledged as collateral against derivative liabilities.

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