Derivative Instruments and Hedging Activities (Narrative) (Details) (USD $)	6 Months Ended
Jan. 31, 2013 MMBbls	Jan. 31, 2012
Gain (loss) recognized in earnings related to hedge ineffectiveness	$ 0	$ 0
Reclassification of net gain to earnings during next 12 months	3,000,000
Reclassification of gain (loss) to earnings from discontinuance of cash flow hedges	0	0
Number of barrells of propane covered by cash flow hedges	1,200,000
Derivative amount of credit risk	1,400,000
Derivative, Net Liability Position, Aggregate Fair Value	1,600,000
Collateral Already Posted, Aggregate Fair Value	1,600,000
Additional Collateral, Aggregate Fair Value	0
Ferrellgas, L.P. [Member]
Gain (loss) recognized in earnings related to hedge ineffectiveness	0	0
Reclassification of net gain to earnings during next 12 months	3,000,000
Reclassification of gain (loss) to earnings from discontinuance of cash flow hedges	0	0
Number of barrells of propane covered by cash flow hedges	1,200,000
Derivative amount of credit risk	1,400,000
Derivative, Net Liability Position, Aggregate Fair Value	1,600,000
Collateral Already Posted, Aggregate Fair Value	1,600,000
Additional Collateral, Aggregate Fair Value	$ 0

Derivative amount of credit risk if counterparties failed to perform contracts

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- Definition

Number of barrells of propane covered by cash flow hedges

+ References

No definition available.

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- Definition

The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4H

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-Name Statement of Financial Accounting Standard (FAS)

-Number 133

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- Definition

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 30

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-Paragraph 1

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- Definition

The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44D

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain (loss) on that instrument.

+ References

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

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- Definition

The net gain (loss) recognized in earnings during the reporting period representing the amount of the cash flow hedges' ineffectiveness.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

The amount of net gain (loss) reclassified into earnings in the period when cash flow hedge is discontinued because it is probable that the original forecasted transactions will not occur by the end of the original period or an additional two month time period.

+ References

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

-Publisher FASB

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-SubTopic 30

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-Paragraph 1

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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