Accounts And Notes Receivable, Net (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Oct. 31, 2011	Jul. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds to Ferrellgas from securitizing receivables to a commercial paper conduit	$ 81.0	$ 61.0
Available proceeds from additional trade accounts receivable	8.0	3.0
Ferrellgas, L.P. And Subsidiaries [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds to Ferrellgas from securitizing receivables to a commercial paper conduit	81.0	61.0
Available proceeds from additional trade accounts receivable	8.0	3.0
Accounts Receivable Securitization [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted average discount rate to value the retained interest in the transferred receivables	3.20%	3.60%
Accounts Receivable Securitization [Member] | Ferrellgas, L.P. And Subsidiaries [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Weighted average discount rate to value the retained interest in the transferred receivables	3.20%	3.60%
Commercial Paper [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Pledged trade receivable as collateral against collateralized notes payable	139.5
Note payable to Ferrellgas, L.P.	81.0
Commercial Paper [Member] | Ferrellgas, L.P. And Subsidiaries [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Pledged trade receivable as collateral against collateralized notes payable	139.5
Note payable to Ferrellgas, L.P.	81.0
Maximum [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds to Ferrellgas from securitizing receivables to a commercial paper conduit	145.0
Maximum [Member] | Ferrellgas, L.P. And Subsidiaries [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Proceeds to Ferrellgas from securitizing receivables to a commercial paper conduit	$ 145.0