Goodwill And Intangible Assets, Net (Aggregate Amortization Expense) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010
Aggregate amortization expense	$ 21,604	$ 23,766	$ 21,180
Ferrellgas, L.P. [Member]
Aggregate amortization expense	$ 21,604	$ 23,766	$ 21,180