Debt (Covenants Narrative) (Details) (USD $) In Millions	Jul. 31, 2011	Jul. 31, 2010
Estimated fair value of long-term debt	$ 1,134.2	$ 1,231.8
Ferrellgas, L.P. And Subsidiaries [Member]
Estimated fair value of long-term debt	$ 941.3	$ 940.6