Derivative Instruments and Hedging Activities (Fair Value of Financial Derivatives Balance Sheet Locations) (Details) - USD ($) $ in Thousands	Jul. 31, 2017	Jul. 31, 2016
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management assets	$ 16,212	$ 8,241
Interest Rate Derivative Assets, at Fair Value	583	5,830
Derivative Asset, Fair Value, Gross Asset	16,795	14,071
Derivatives - Price risk management liabilities	1,258	17,689
Interest Rate Derivative Liabilities, at Fair Value	707	3,553
Derivative Liability, Fair Value, Gross Liability	1,965	21,242
Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management assets	16,212	8,241
Interest Rate Derivative Assets, at Fair Value	583	5,830
Derivative Asset, Fair Value, Gross Asset	16,795	14,071
Derivatives - Price risk management liabilities	1,258	17,689
Interest Rate Derivative Liabilities, at Fair Value	707	3,553
Derivative Liability, Fair Value, Gross Liability	1,965	21,242
Prepaid Expenses and Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management assets	11,061	2,263
Interest Rate Derivative Assets, at Fair Value	583	1,654
Interest Rate Derivative Instruments Not Designated as Hedging Instruments at Fair Value, Net		0
Prepaid Expenses and Other Current Assets [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management assets	11,061	2,263
Interest Rate Derivative Assets, at Fair Value	583	1,654
Interest Rate Derivative Instruments Not Designated as Hedging Instruments at Fair Value, Net		0
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management liabilities	415	10,184
Interest Rate Derivative Liabilities, at Fair Value	595	2,309
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value		3,996
Other Current Liabilities [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management liabilities	415	10,184
Interest Rate Derivative Liabilities, at Fair Value	595	2,309
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value		3,996
Other Assets, Net [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management assets	4,413	3,056
Interest Rate Derivative Assets, at Fair Value	0	4,176
Other Assets, Net [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management assets	4,413	3,056
Interest Rate Derivative Assets, at Fair Value	0	4,176
Interest Rate Derivative Instruments Not Designated as Hedging Instruments at Fair Value, Net		2,922
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management liabilities	15	1,597
Interest Rate Derivative Liabilities, at Fair Value	112	1,244
Other Liabilities [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management liabilities	15	1,597
Interest Rate Derivative Liabilities, at Fair Value	112	1,244
Derivative Instruments Not Designated as Hedging Instruments, Liability, at Fair Value		1,912
Midstream - Crude Oil Logistics [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Interest Rate Derivative Instruments Not Designated as Hedging Instruments at Fair Value, Net	738	2,922
Midstream - Crude Oil Logistics [Member] | Prepaid Expenses and Other Current Assets [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Interest Rate Derivative Instruments Not Designated as Hedging Instruments at Fair Value, Net	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	828	$ 1,912
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	$ 828