Derivative Instruments and Hedging Activities (Fair Value of Financial Derivatives Balance Sheet Locations) (Details) - USD ($) $ in Thousands	Oct. 31, 2017	Jul. 31, 2017
Derivatives, Fair Value [Line Items]
Propane commodity derivative assets	$ 35,000	$ 16,212
Interest rate swap assets	298	583
Derivative assets, fair value	35,298	16,795
Propane commodity derivative liabilities	3,464	1,258
Interest rate swap liabilities	984	707
Derivative liabilities, fair value	4,448	1,965
Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Propane commodity derivative assets	35,000	16,212
Interest rate swap assets	298	583
Derivative assets, fair value	35,298	16,795
Propane commodity derivative liabilities	3,464	1,258
Interest rate swap liabilities	984	707
Derivative liabilities, fair value	4,448	1,965
Prepaid Expenses and Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Propane commodity derivative assets	25,938	11,061
Interest rate swap assets	298	583
Prepaid Expenses and Other Current Assets [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Propane commodity derivative assets	25,938	11,061
Interest rate swap assets	298	583
Other assets, net [Member]
Derivatives, Fair Value [Line Items]
Propane commodity derivative assets	8,789	4,413
Interest rate swap assets	0	0
Other assets, net [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Propane commodity derivative assets	8,789	4,413
Interest rate swap assets	0	0
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Propane commodity derivative liabilities	1,209	415
Interest rate swap liabilities	284	595
Other Current Liabilities [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Propane commodity derivative liabilities	1,209	415
Interest rate swap liabilities	284	595
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Propane commodity derivative liabilities	284	15
Interest rate swap liabilities	700	112
Other Liabilities [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Propane commodity derivative liabilities	284	15
Interest rate swap liabilities	700	112
Midstream - Crude Oil Logistics [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Other Derivatives Not Designated as Hedging Instruments at Fair Value, Net	273	738
Midstream - Crude Oil Logistics [Member] | Prepaid Expenses and Other Current Assets [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Other Derivatives Not Designated as Hedging Instruments at Fair Value, Net	273	738
Midstream - Crude Oil Logistics [Member] | Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	1,971	828
Midstream - Crude Oil Logistics [Member] | Other Current Liabilities [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value	$ 1,971	$ 828