Derivative Instruments and Hedging Activities (Changes in Derivative Value Effect on Other Comprehensive Income Loss) (Details) (USD $) In Thousands, unless otherwise specified					6 Months Ended
	Jan. 31, 2013	Jul. 31, 2012	Jan. 31, 2013 Ferrellgas, L.P. [Member]	Jul. 31, 2012 Ferrellgas, L.P. [Member]	Jan. 31, 2013 Derivative [Member]	Jan. 31, 2012 Derivative [Member]	Jan. 31, 2013 Derivative [Member] Ferrellgas, L.P. [Member]	Jan. 31, 2012 Derivative [Member] Ferrellgas, L.P. [Member]
Beginning balance	$ (4,547)	$ (13,159)	$ (4,581)	$ (13,280)	$ (12,799)	$ 5,161	$ (12,799)	$ 5,161
Change in value on risk management commodity derivatives					914	(3,875)	914	(3,875)
Reclassification of gains (losses) from AOCI(L) to Cost of product sold - propane and other gas liquids					8,625	(2,713)	8,625	(2,713)
Change in value on risk management interest rate derivatives					(843)	0	(843)	0
Ending balance	$ (4,547)	$ (13,159)	$ (4,581)	$ (13,280)	$ (4,103)	$ (1,427)	$ (4,103)	$ (1,427)