Fair Value Measurements (Assets And Liabilities Fair Value Hierarchy) (Details) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2012	Jul. 31, 2011
Commodity derivatives propane swap assets	$ 1,049	$ 7,637
Commodity derivatives propane swap liabilities	(12,069)	(2,476)
Interest rate swap assets	7,784
Interest rate swap liabilities	(1,778)
Ferrellgas, L.P. [Member]
Commodity derivatives propane swap assets	1,049	7,637
Commodity derivatives propane swap liabilities	(12,069)	(2,476)
Interest rate swap assets	7,784
Interest rate swap liabilities	(1,778)
Level 2 [Member]
Commodity derivatives propane swap assets	1,049	7,637
Commodity derivatives propane swap liabilities	(12,069)	(2,476)
Interest rate swap assets	7,784
Interest rate swap liabilities	(1,778)
Level 2 [Member] | Ferrellgas, L.P. [Member]
Commodity derivatives propane swap assets	1,049	7,637
Commodity derivatives propane swap liabilities	(12,069)	(2,476)
Interest rate swap assets	7,784
Interest rate swap liabilities	$ (1,778)