Derivatives (Cash Flow Hedge Activity Included In OCI) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
Jan. 31, 2012	Jan. 31, 2011
Fair value gain (loss) adjustment classified as OCI with offset in Price risk management assets and Price risk management liabilities	$ (3,875)	$ 11,780
Reclassification of net gains originally recorded within OCI to Cost of product sold - propane and other gas liquids	2,713	3,240
Ferrellgas, L.P. [Member]
Fair value gain (loss) adjustment classified as OCI with offset in Price risk management assets and Price risk management liabilities	(3,875)
Reclassification of net gains originally recorded within OCI to Cost of product sold - propane and other gas liquids	$ 2,713

The amount of net gains or losses on a cash flow hedge reclassified in the period to cost of sales from accumulated other comprehensive income.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 45

-Subparagraph b

-Clause 1

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5624171-113959

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6887037&loc=d3e80784-113994

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