Accounts And Notes Receivable, Net And Accounts Receivable Securitization (Narrative) (Details) - USD ($)
6 Months Ended 12 Months Ended
Jan. 31, 2016
Jul. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Accounts receivable pledged as collateral $ 190,063,000 $ 123,791,000
Ferrellgas, L.P. [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Accounts receivable pledged as collateral 190,063,000 123,791,000
Accounts Receivable Securitization [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Accounts receivable pledged as collateral 190,100,000 123,800,000
Collateralized notes payable 119,000,000 70,000,000
Proceeds from accounts receivable securitization 119,000,000 70,000,000
Available proceeds from additional trade accounts receivable $ 0 $ 0
Weighted average interest rate on borrowings under accounts receivable securitization 2.90% 2.30%
Accounts Receivable Securitization [Member] | Ferrellgas, L.P. [Member]    
Accounts, Notes, Loans and Financing Receivable [Line Items]    
Accounts receivable pledged as collateral $ 190,100,000 $ 123,800,000
Collateralized notes payable 119,000,000 70,000,000
Proceeds from accounts receivable securitization 119,000,000 70,000,000
Available proceeds from additional trade accounts receivable $ 0 $ 0
Weighted average interest rate on borrowings under accounts receivable securitization 2.90% 2.30%