Number of persons employed by the Entity

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Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount represents the contributions received from the partnership related to forming the corporation.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount represents the number of shares granted to the partnership related to forming the corporation.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Number Of Entity Subsidiaries

+ References

No definition available.

+ Details

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Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of general partners in the entity.

+ References

No definition available.

+ Details

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Namespace Prefix:	fgp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of general partners added in the amendment to the limited partnership agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	fgp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 210
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
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-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

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

- Definition

Percentage investment held by the managing member or general partner of the limited liability company (LLC) or limited partnership (LP).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The number of states the entity operates in as of the balance sheet date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of units or percentage investment held in the subsidiary by the limited liability company or limited partnership.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

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Name:	us-gaap_DebtInstrumentAxis=fgp_FixedRateSixPointFiveZeroDueTwoThousandTwentyOneMember
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Name:	srt_OwnershipAxis=fgp_FerrellgasPartnersLpMember
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- Details

Name:	dei_LegalEntityAxis=fgp_FerrellgasPartnersLpMember
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Name:	srt_OwnershipAxis=fgp_FerrellgasPartnersFinanceCorpMember
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Name:	dei_LegalEntityAxis=fgp_FerrellCompaniesMember
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Partnership Organization And Formation (Details)		12 Months Ended
Partnership Organization And Formation (Details)	Apr. 24, 2020 item	Jul. 31, 2020 USD ($) employee state item subsidiary shares	Jul. 31, 2019 shares	Jan. 31, 2017 USD ($)	Nov. 30, 2010 USD ($)	Apr. 30, 2010 USD ($)
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Number of subsidiaries \| subsidiary		2
Number of states in which entity operates \| state		50
Number of employees \| employee		0
Fixed Rate Eight Point Six Two Five Due Two Thousand Twenty [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Aggregate principal amount		$ 357,000,000		$ 175,000,000		$ 280,000,000
Fixed Rate Six Point Five Zero Due Two Thousand Twenty One [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Aggregate principal amount					$ 500,000,000
Ferrellgas Partners LP [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
General partner ownership interest		2.00%	2.00%
Ferrellgas, L.P. [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Number of general partners \| item		3
Ferrellgas Partners LP [Member] \| Fixed Rate Six Point Five Zero Due Two Thousand Twenty One [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Aggregate principal amount		$ 500,000,000
Ferrellgas Partners LP [Member] \| Ferrellgas, L.P. [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Limited partner interest		99.00%
Ferrellgas Partners LP [Member] \| Ferrellgas Partners Finance Corp. [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership percentage		100.00%
Ferrell Companies [Member] \| Ferrellgas Partners LP [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Common stock shares outstanding \| shares		22,800,000
Ferrellgas Inc., General Partner [Member] \| Ferrellgas [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
General partner ownership interest		2.00%
Ferrellgas Inc., General Partner [Member] \| Ferrellgas Partners LP [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
General partner ownership interest		1.00%
Ferrellgas Inc., General Partner [Member] \| Ferrellgas, L.P. [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
General partner ownership interest		1.0101%	1.0101%
Ferrellgas, L.P. [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Number of general partners \| item		3
Number of states in which entity operates \| state		50
Number of employees \| employee		0
Number of additional general partners \| item	2
Ferrellgas, L.P. [Member] \| Fixed Rate Six Point Five Zero Due Two Thousand Twenty One [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Aggregate principal amount		$ 500,000,000			$ 500,000,000
Ferrellgas, L.P. [Member] \| Ferrellgas [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership percentage		100.00%
Ferrellgas, L.P. [Member] \| Ferrellgas Finance Corp. [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Ownership percentage		100.00%
Ferrellgas Partners Finance Corp. [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Common stock shares outstanding \| shares		1,000	1,000
Corporation formation proceeds from partnership		$ 1,000
Corporation formation shares granted to partnership \| shares		1,000
Number of employees \| employee		0
Ferrellgas Finance Corp. [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Common stock shares outstanding \| shares		1,000	1,000
Corporation formation proceeds from partnership		$ 1,000
Corporation formation shares granted to partnership \| shares		1,000
Number of employees \| employee		0
Ferrellgas Finance Corp. [Member] \| Fixed Rate Six Point Five Zero Due Two Thousand Twenty One [Member]
Subsidiary of Limited Liability Company or Limited Partnership [Line Items]
Aggregate principal amount		$ 500,000,000