Debt (Senior Notes Narrative) (Details) (Imported) (USD $)	12 Months Ended			12 Months Ended		1 Months Ended	12 Months Ended			1 Months Ended	12 Months Ended			1 Months Ended			12 Months Ended				12 Months Ended		12 Months Ended
	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2012	Jul. 31, 2011 Ferrellgas, L.P. [Member]	Jul. 31, 2010 Ferrellgas, L.P. [Member]	Nov. 30, 2010 Fixed Rate, 6.50%, Due 2021 [Member]	Jul. 31, 2012 Fixed Rate, 6.50%, Due 2021 [Member]	Jul. 31, 2011 Fixed Rate, 6.50%, Due 2021 [Member]	Nov. 24, 2010 Fixed Rate, 6.50%, Due 2021 [Member]	Nov. 30, 2010 Fixed Rate, 6.50%, Due 2021 [Member] Ferrellgas, L.P. [Member]	Jul. 31, 2012 Fixed Rate, 6.50%, Due 2021 [Member] Ferrellgas, L.P. [Member]	Jul. 31, 2011 Fixed Rate, 6.50%, Due 2021 [Member] Ferrellgas, L.P. [Member]	Nov. 24, 2010 Fixed Rate, 6.50%, Due 2021 [Member] Ferrellgas, L.P. [Member]	Nov. 30, 2010 Fixed Rate, 6.75%, Due 2014 [Member]	Nov. 30, 2010 Fixed Rate, 6.75%, Due 2014 [Member] Ferrellgas, L.P. [Member]	Mar. 31, 2011 Fixed Rate, 8.625%, Due 2020 [Member]	Jul. 31, 2012 Fixed Rate, 8.625%, Due 2020 [Member]	Jul. 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 Fixed Rate, 9.125%, Due 2017 [Member]	Sep. 14, 2009 Fixed Rate, 9.125%, Due 2017 [Member]	Jul. 31, 2012 Fixed Rate, 9.125%, Due 2017 [Member] Ferrellgas, L.P. [Member]	Sep. 14, 2009 Fixed Rate, 9.125%, Due 2017 [Member] Ferrellgas, L.P. [Member]
Debt instrument prepayment penalty prior to date							2019				2019						2018				2015		2015
Debt instrument, face amount									$ 500,000,000				$ 500,000,000					$ 280,000,000	$ 280,000,000	$ 280,000,000		$ 300,000,000		$ 300,000,000
Interest rate			9.125%						6.50%				6.50%	6.75%	6.75%			8.625%		8.625%
Debt instrument, maturity year									2021				2021	2014	2014			2020		2020		2017		2017
Proceeds from issuance of unsecured debt						491,300,000				491,300,000
Debt redeemed								500,000,000				500,000,000		450,000,000	450,000,000	98,000,000		98,000,000		98,000,000
Make-whole payment														11,100,000	11,100,000	8,400,000		8,400,000
Accrued interest paid														2,400,000	2,400,000	2,400,000
Unregistered notes, issuance date								Nov. 24, 2010				Nov. 24, 2010					Apr. 13, 2010
Write-offs of unamortized discount on debt														25,300,000	25,300,000	2,200,000
Prepayment premium for early extinguishment of debt	(46,962,000)	(20,716,000)		(36,449,000)	(17,308,000)
Debt Instrument, Frequency of Periodic Payment							semi-annually										semi-annually				semi-annually
Debt Instrument, Unamortized Discount																						$ 4,200,000		$ 4,200,000
Debt Instrument, Maturity Date							May 01, 2021				May 01, 2021										Oct. 01, 2017		Oct. 01, 2017