Debt Debt (Components of Long-Term Debt) (Details) - USD ($)
$ in Thousands
Jan. 31, 2016
Jul. 31, 2015
Schedule of Capitalization, Long-term Debt [Line Items]    
Long-term debt $ 1,894,790 $ 1,804,392
Short-term borrowings 86,200 75,319
Ferrellgas, L.P. [Member]    
Schedule of Capitalization, Long-term Debt [Line Items]    
Long-term debt 1,712,790 1,622,392
Short-term borrowings $ 86,200 $ 75,319
Secured Credit Facility [Member]    
Schedule of Capitalization, Long-term Debt [Line Items]    
Debt weighted average interest rate 3.70% 3.50%
Secured Credit Facility [Member] | Ferrellgas, L.P. [Member]    
Schedule of Capitalization, Long-term Debt [Line Items]    
Debt weighted average interest rate 3.70% 3.50%