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

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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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-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

The average effective interest rate during the reporting period.

+ 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
-URI http://asc.fasb.org/extlink&oid=114775744&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Balance Type:	na
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- 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.

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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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

- Definition

The effective interest rate at the end of the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

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

- Definition

The carrying value as of the balance sheet date of the current portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
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Period Type:	instant

- Details

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- Details

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Debt - Secured Credit Facilities (Details) - USD ($)	9 Months Ended	12 Months Ended
Debt - Secured Credit Facilities (Details) - USD ($)	Apr. 30, 2019	Jul. 31, 2018	May 04, 2018
Debt Instrument [Line Items]
Available borrowing capacity	$ 49,000,000	$ 0
Short-term borrowings	0	32,800,000
Letters of credit outstanding	102,100,000	107,900,000
Senior Secured Credit Facility Entered 2018 May [Member]
Debt Instrument [Line Items]
Secured line of credit facility			$ 575,000,000
Term Loan Due 2023 May 4 [Member]
Debt Instrument [Line Items]
Aggregate principal amount	$ 275,000,000	$ 275,000,000
Term loan rate, as a percent	8.26%	7.86%
Secured line of credit facility			275,000,000
Revolving Facility Under Senior Secured Credit Facility Entered 2018 May [Member]
Debt Instrument [Line Items]
Available borrowing capacity	$ 197,900,000	$ 159,300,000
Short-term borrowings	0	$ 32,800,000
Credit facility interest rate		9.75%
Secured line of credit facility			300,000,000
Letter of Credit [Member]
Debt Instrument [Line Items]
Available borrowing capacity	22,900,000	$ 17,100,000
Ferrellgas, L.P. [Member]
Debt Instrument [Line Items]
Available borrowing capacity	49,000,000	0
Short-term borrowings	0	32,800,000
Letters of credit outstanding	102,100,000	107,900,000
Ferrellgas, L.P. [Member] \| Senior Secured Credit Facility Entered 2018 May [Member]
Debt Instrument [Line Items]
Secured line of credit facility			575,000,000
Ferrellgas, L.P. [Member] \| Term Loan Due 2023 May 4 [Member]
Debt Instrument [Line Items]
Aggregate principal amount	$ 275,000,000	$ 275,000,000
Term loan rate, as a percent	8.26%	7.86%
Secured line of credit facility			275,000,000
Ferrellgas, L.P. [Member] \| Revolving Facility Under Senior Secured Credit Facility Entered 2018 May [Member]
Debt Instrument [Line Items]
Available borrowing capacity	$ 197,900,000	$ 159,300,000
Short-term borrowings	0	$ 32,800,000
Credit facility interest rate		9.75%
Secured line of credit facility			$ 300,000,000
Ferrellgas, L.P. [Member] \| Letter of Credit [Member]
Debt Instrument [Line Items]
Available borrowing capacity	$ 22,900,000	$ 17,100,000