Fair Value Measurements (Assets And Liabilities Fair Value Hierarchy) (Details) (USD $) In Thousands, unless otherwise specified	Oct. 31, 2012	Jul. 31, 2012
Interest rate swap assets	$ 7,311	$ 7,784
Commodity derivatives propane swap assets	4,166	1,049
Interest rate swap liabilities	(2,028)	(1,778)
Commodity derivatives propane swap liabilities	(4,469)	(12,069)
Ferrellgas, L.P. [Member]
Interest rate swap assets	7,311	7,784
Commodity derivatives propane swap assets	4,166	1,049
Interest rate swap liabilities	(2,028)	(1,778)
Commodity derivatives propane swap liabilities	(4,469)	(12,069)
Level 2 [Member]
Interest rate swap assets	7,311	7,784
Commodity derivatives propane swap assets	4,166	1,049
Interest rate swap liabilities	(2,028)	(1,778)
Commodity derivatives propane swap liabilities	(4,469)	(12,069)
Level 2 [Member] | Ferrellgas, L.P. [Member]
Interest rate swap assets	7,311	7,784
Commodity derivatives propane swap assets	4,166	1,049
Interest rate swap liabilities	(2,028)	(1,778)
Commodity derivatives propane swap liabilities	$ (4,469)	$ (12,069)