Derivative Instruments and Hedging Activities (Cash Flow Hedge Derivative Effect on Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011
Derivative [Member]
Amount of gain (loss) recognized in AOCI(L) on derivative	$ 4,252	$ (25,068)
Amount of gain (loss) reclassified from AOCI into income	(10,613)	(7,108)
Derivative [Member] | Ferrellgas, L.P. [Member]
Amount of gain (loss) recognized in AOCI(L) on derivative	4,252	(25,068)
Amount of gain (loss) reclassified from AOCI into income	(10,613)	(7,108)
Commodity Derivatives Propane [Member]
Amount of gain (loss) recognized in AOCI(L) on derivative	2,032	(23,290)	22,676
Amount of gain (loss) reclassified from AOCI into income	(10,613)	(7,108)	17,358
Commodity Derivatives Propane [Member] | Ferrellgas, L.P. [Member]
Amount of gain (loss) recognized in AOCI(L) on derivative	2,032	(23,290)	22,676
Amount of gain (loss) reclassified from AOCI into income	(10,613)	(7,108)	17,358
Interest Rate Swap [Member]
Amount of gain (loss) recognized in AOCI(L) on derivative	2,220	(1,778)	0
Interest Rate Swap [Member] | Ferrellgas, L.P. [Member]
Amount of gain (loss) recognized in AOCI(L) on derivative	2,220	(1,778)	0
Cost of Sales [Member] | Commodity Derivatives Propane [Member]
Amount of gain (loss) reclassified from AOCI into income	(10,613)	(7,108)
Cost of Sales [Member] | Commodity Derivatives Propane [Member] | Ferrellgas, L.P. [Member]
Amount of gain (loss) reclassified from AOCI into income	(10,613)	(7,108)
Interest Expense [Member] | Interest Rate Swap [Member]
Amount of gain (loss) reclassified from AOCI into income	0	0
Interest Expense [Member] | Interest Rate Swap [Member] | Ferrellgas, L.P. [Member]
Amount of gain (loss) reclassified from AOCI into income	$ 0	$ 0