Partners' Capital (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended			3 Months Ended	12 Months Ended														12 Months Ended
	Jul. 31, 2012	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2012 Ferrellgas, L.P. [Member]	Jul. 31, 2012 Ferrellgas, L.P. [Member]	Jul. 31, 2011 Ferrellgas, L.P. [Member]	Jul. 31, 2012 Ferrellgas Partners [Member]	Jul. 31, 2012 Ferrellgas Partners [Member] Ferrellgas, L.P. [Member]	Jul. 31, 2011 Ferrellgas Partners [Member] Ferrellgas, L.P. [Member]	Jul. 31, 2012 General Partner [Member]	Jul. 31, 2011 General Partner [Member]	Jul. 31, 2012 General Partner [Member] Ferrellgas, L.P. [Member]	Jul. 31, 2011 General Partner [Member] Ferrellgas, L.P. [Member]	Jul. 31, 2012 Ferrell Companies [Member]	Jul. 31, 2011 Fixed Rate, 8.625%, Due 2020 [Member]	Mar. 31, 2011 Fixed Rate, 8.625%, Due 2020 [Member]	Apr. 13, 2010 Fixed Rate, 8.625%, Due 2020 [Member]	Jul. 31, 2011 Fixed Rate, 8.625%, Due 2020 [Member] Ferrellgas, L.P. [Member]	Jul. 31, 2012 Institutional Investor [Member]	Jul. 31, 2011 Institutional Investor [Member]	Jul. 31, 2011 Original Offering [Member]	Jul. 31, 2011 Over-Allotment [Member]
Distribution Made to Member or Limited Partner [Line Items]
Received cash contributions from parent									$ 50,700,000	$ 157,700,000
Cash distribution paid to partners										107,900,000
Asset contributions received from parent						1,300,000	2,900,000
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest								98.00%			2.00%	2.00%	1.0101%	1.0101%
Minimum percentage ownership of outstanding common units resulting in non voting of owners		20.00%
Cash distribution declared date	Aug. 23, 2012				Aug. 23, 2012
Cash distributions declared per common unit	$ 0.50
Cash distributions, payment date	Sep. 14, 2012				Sep. 14, 2012
Distribution payable, amount									39,900,000				400,000
Offering of common units, shares															1,400,000					1,500,000	1,200,000
Proceeds from offering of common units			127,300,000												25,000,000					25,000,000	30,000,000
Stock issued during the period for acquisition, shares		100,000	100,000
Stock issued during the period for acquisition, value		1,300,000	2,900,000
Cash received from contributions		511,000	1,594,000	214,000							1,100,000	3,300,000	500,000	1,600,000
Non-cash contributions											400,000	500,000	200,000	200,000
Debt redeemed																98,000,000	98,000,000		98,000,000
Debt instrument, face amount																280,000,000		280,000,000	280,000,000
Debt instrument, fixed interest rate	9.125%	9.125%														8.625%			8.625%
Debt maturity year																2020			2020
Debt instrument, make whole payment																8,400,000	8,400,000
Accrued interest	$ 19,945,000	$ 19,945,000	$ 19,779,000		$ 17,938,000	$ 17,938,000	$ 17,773,000									$ 2,400,000
Subsidiary Or Equity Method Investee Cumulative Percentage Ownership After All Transactions And Including Beneficial Ownership															27.50%
Total beneficial ownership															27.50%
Public offering for common units			5,100,000																			4,400,000	700,000