Guarantor financial information Guarantor financial information - Narrative (Details) $ in Millions	Jul. 31, 2017 USD ($)
Ferrellgas, L.P. [Member]
Condensed Financial Statements, Captions [Line Items]
Equity Method Investment, Ownership Percentage	100.00%
Fixed Rate Six Point Seven Five Due Two Thousand Twenty Three [Member]
Condensed Financial Statements, Captions [Line Items]
Debt Instrument, Face Amount	$ 500.0
Debt instrument, fixed interest rate	6.75%
Fixed Rate Six Point Seven Five Due Two Thousand Twenty Three [Member] \| Ferrellgas, L.P. [Member]
Condensed Financial Statements, Captions [Line Items]
Debt Instrument, Face Amount	$ 500.0
Debt instrument, fixed interest rate	6.75%

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.

No definition available.

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

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