Fair Value Measurements (Assets And Liabilities Fair Value Hierarchy) (Details) - USD ($)
$ in Thousands
Jan. 31, 2016
Jul. 31, 2015
Interest rate swap assets $ 3,890 $ 1,828
Propane commodity derivative assets 6,957 4,655
Interest rate swap liabilities (4,210) (4,748)
Propane commodity derivative liabilities (42,745) (42,375)
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value 0 (100)
Ferrellgas, L.P. [Member]    
Interest rate swap assets 3,890 1,828
Propane commodity derivative assets 6,957 4,655
Interest rate swap liabilities (4,210) (4,748)
Propane commodity derivative liabilities (42,745) (42,375)
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value 0 (100)
Fair Value, Inputs, Level 1 [Member]    
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value   0
Fair Value, Inputs, Level 1 [Member] | Ferrellgas, L.P. [Member]    
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value   0
Fair Value, Inputs, Level 2 [Member]    
Interest rate swap assets 3,890 1,828
Propane commodity derivative assets 6,957 4,655
Interest rate swap liabilities (4,210) (4,748)
Propane commodity derivative liabilities (42,745) (42,375)
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value   0
Fair Value, Inputs, Level 2 [Member] | Ferrellgas, L.P. [Member]    
Interest rate swap assets 3,890 1,828
Propane commodity derivative assets 6,957 4,655
Interest rate swap liabilities (4,210) (4,748)
Propane commodity derivative liabilities $ (42,745) (42,375)
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value   0
Fair Value, Inputs, Level 3 [Member]    
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value   (100)
Fair Value, Inputs, Level 3 [Member] | Ferrellgas, L.P. [Member]    
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value   $ (100)