Debt Debt (Long-Term Debt Parenthetical) (Details) - USD ($) $ in Thousands	12 Months Ended
Jul. 31, 2017	Jul. 31, 2016
Debt Instrument [Line Items]
Short-term borrowings	$ 59,781	$ 101,291
Fixed Rate Six Point Five Zero Due Two Thousand Twenty One [Member]
Debt Instrument [Line Items]
Debt instrument, fixed interest rate	6.50%
Debt maturity year	2021
Fixed Rate Six Point Seven Five Due Two Thousand Twenty Three [Member]
Debt Instrument [Line Items]
Debt instrument, fixed interest rate	6.75%
Debt maturity year	2023
Fixed Rate Six Point Seven Five Due Two Thousand twenty Two [Domain]
Debt Instrument [Line Items]
Debt instrument, fixed interest rate	6.75%
Debt Instrument, Maturity Date	Nov. 01, 2022
Debt Instrument, Unamortized Premium	$ 3,166	4,008
Fixed Rate Eight Point Six Two Five Due Two Thousand Twenty [Member]
Debt Instrument [Line Items]
Debt instrument, fixed interest rate	8.625%
Debt maturity year	2020
Debt Instrument, Unamortized Discount	$ 5,976	0
Secured Credit Facility [Member]
Debt Instrument [Line Items]
Debt maturity year	2018
Short-term borrowings	$ 59,781	$ 101,291
Debt, Weighted Average Interest Rate	6.00%	3.70%
Notes Payable [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount	$ 1,128	$ 1,566
Debt Instrument Maturity Year Range Start	2018
Debt, Weighted Average Interest Rate	12.00%	11.80%
Debt Instrument Maturity Year Range End	2022
Ferrellgas, L.P. [Member]
Debt Instrument [Line Items]
Short-term borrowings	$ 59,781	$ 101,291
Ferrellgas, L.P. [Member] \| Fixed Rate Six Point Five Zero Due Two Thousand Twenty One [Member]
Debt Instrument [Line Items]
Debt instrument, fixed interest rate	6.50%
Debt maturity year	2021
Ferrellgas, L.P. [Member] \| Fixed Rate Six Point Seven Five Due Two Thousand Twenty Three [Member]
Debt Instrument [Line Items]
Debt instrument, fixed interest rate	6.75%
Debt maturity year	2023
Ferrellgas, L.P. [Member] \| Fixed Rate Six Point Seven Five Due Two Thousand twenty Two [Domain]
Debt Instrument [Line Items]
Debt instrument, fixed interest rate	6.75%
Debt Instrument, Maturity Date	Nov. 01, 2022
Debt Instrument, Unamortized Premium	$ 3,166	4,008
Ferrellgas, L.P. [Member] \| Secured Credit Facility [Member]
Debt Instrument [Line Items]
Debt maturity year	2018
Short-term borrowings	$ 59,781	$ 101,291
Debt, Weighted Average Interest Rate	6.00%	3.70%
Ferrellgas, L.P. [Member] \| Notes Payable [Member]
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount	$ 1,128	$ 1,566
Debt Instrument Maturity Year Range Start	2018
Debt, Weighted Average Interest Rate	12.00%	11.80%
Debt Instrument Maturity Year Range End	2022

Debt Instrument Maturity Year Range End

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- Definition

Debt Instrument Maturity Year Range Start

+ References

No definition available.

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- Definition

Debt maturity year

+ References

No definition available.

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- Definition

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

+ References

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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

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

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- Definition

Amount, after accumulated amortization, of debt discount.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28541-108399

Reference 2: 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

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- Definition

Amount, after accumulated amortization, of debt premium.

+ References

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- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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- Definition

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

+ 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(19)(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16)(a)(1))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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