Debt Debt (Components of Long-Term Debt) (Details) - USD ($) $ in Thousands	Oct. 31, 2016	Jul. 31, 2016
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term debt	$ 1,965,219	$ 1,941,335
Short-term borrowings	96,824	101,291
Ferrellgas, L.P. [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term debt	1,784,660	1,760,881
Short-term borrowings	$ 96,824	$ 101,291
Secured Credit Facility [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt weighted average interest rate	4.10%	3.70%
Secured Credit Facility [Member] | Ferrellgas, L.P. [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt weighted average interest rate	4.10%	3.70%