Fair Value Measurements (Assets And Liabilities Fair Value Hierarchy) (Details) (USD $) In Thousands, unless otherwise specified	Jan. 31, 2013	Jul. 31, 2012
Interest rate swap agreement assets	$ 8,008	$ 7,784
Commodity derivatives propane swap assets	2,133	1,049
Interest rate swap agreement liabilities	(2,622)	(1,778)
Commodity derivatives propane swap liabilities	(3,613)	(12,069)
Ferrellgas, L.P. [Member]
Interest rate swap agreement assets	8,008	7,784
Commodity derivatives propane swap assets	2,133	1,049
Interest rate swap agreement liabilities	(2,622)	(1,778)
Commodity derivatives propane swap liabilities	(3,613)	(12,069)
Level 2 [Member]
Interest rate swap agreement assets	8,008	7,784
Commodity derivatives propane swap assets	2,133	1,049
Interest rate swap agreement liabilities	(2,622)	(1,778)
Commodity derivatives propane swap liabilities	(3,613)	(12,069)
Level 2 [Member] | Ferrellgas, L.P. [Member]
Interest rate swap agreement assets	8,008	7,784
Commodity derivatives propane swap assets	2,133	1,049
Interest rate swap agreement liabilities	(2,622)	(1,778)
Commodity derivatives propane swap liabilities	$ (3,613)	$ (12,069)