Derivative Instruments and Hedging Activities (Fair Value Interest Rate Derivative Income Location) (Details) (Interest Rate Swap [Member], Interest Expense [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 31, 2012	Oct. 31, 2011
Derivative, Gain (Loss) on Derivative, Net	$ 724
Interest Expense, Debt	(5,469)	(5,469)
Ferrellgas, L.P. [Member]
Derivative, Gain (Loss) on Derivative, Net	724
Interest Expense, Debt	$ (5,469)	$ (5,469)