Subsequent Events (Details) (USD $)	12 Months Ended
Jul. 31, 2011 Ferrellgas, L.P. And Subsidiaries [Member] Minimum [Member]	Jul. 31, 2011 Minimum [Member]	Jul. 31, 2011 Ferrellgas, L.P. And Subsidiaries [Member] Maximum [Member]	Jul. 31, 2011 Maximum [Member]	Sep. 30, 2011 Ferrellgas, L.P. And Subsidiaries [Member] Letter Of Credit [Member] New Secured Credit Facility [Member]	Sep. 30, 2011 Letter Of Credit [Member] New Secured Credit Facility [Member]	Sep. 30, 2011 Secured Credit Facility [Member] New Secured Credit Facility [Member]	Sep. 30, 2011 Ferrellgas, L.P. And Subsidiaries [Member] New Secured Credit Facility [Member]
Secured line of credit facility					$ 200,000,000	$ 200,000,000	$ 400,000,000	$ 400,000,000
Secured credit facility interest rate	1.25%	1.25%	1.50%	1.50%

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 129
-Paragraph 2, 4
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 22
-Article 5

Reference 3: 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(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant