Fair Value Measurements (Assets And Liabilities Fair Value Hierarchy) (Details) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2015	Jul. 31, 2014
Interest rate swap assets	$ 2,145	$ 2,101
Propane commodity derivative assets	5,083	7,006
Interest rate swap liabilities	(3,689)	(5,075)
Propane commodity derivative liabilities	(27,236)	(83)
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	(100)	(6,400)
Ferrellgas, L.P. [Member]
Interest rate swap assets	2,145	2,101
Propane commodity derivative assets	5,083	7,006
Interest rate swap liabilities	(3,689)	(5,075)
Propane commodity derivative liabilities	(27,236)	(83)
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	(100)	(6,400)
Level 1 [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	0	0
Level 1 [Member] \| Ferrellgas, L.P. [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	0	0
Level 2 [Member]
Interest rate swap assets	2,145	2,101
Propane commodity derivative assets	5,083	7,006
Interest rate swap liabilities	(3,689)	(5,075)
Propane commodity derivative liabilities	(27,236)	(83)
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	0	0
Level 2 [Member] \| Ferrellgas, L.P. [Member]
Interest rate swap assets	2,145	2,101
Propane commodity derivative assets	5,083	7,006
Interest rate swap liabilities	(3,689)	(5,075)
Propane commodity derivative liabilities	(27,236)	(83)
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	0	0
Level 3 [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	(100)	(6,400)
Level 3 [Member] \| Ferrellgas, L.P. [Member]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	$ (100)	$ (6,400)

Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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.

+ References

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=35750535&loc=d3e13433-108611

+ Details

Name:	us-gaap_InterestRateDerivativeAssetsAtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

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

+ References

+ Details

Name:	us-gaap_InterestRateDerivativeLiabilitiesAtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

+ Details

Name:	us-gaap_PriceRiskDerivativeAssetsAtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value as of the balance sheet date of price risk derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as liabilities on the balance sheet.

+ References

+ Details

Name:	us-gaap_PriceRiskDerivativeLiabilitiesAtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	dei_LegalEntityAxis=fgp_FerrellgasLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: