Derivative Instruments and Hedging Activities Derivative Instruments and Hedging Activities (Schedule of Derivative Collateral) (Details) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2015	Jul. 31, 2014
Derivative Asset, Fair Value of Collateral	$ 21,821	$ 345
Derivative Liability, Fair Value of Collateral	15	0
Ferrellgas, L.P. [Member]
Derivative Asset, Fair Value of Collateral	21,821	345
Derivative Liability, Fair Value of Collateral	15	0
Other assets, net [Member]
Derivative Asset, Fair Value of Collateral	5,279	189
Other assets, net [Member] | Ferrellgas, L.P. [Member]
Derivative Asset, Fair Value of Collateral	5,279	189
Prepaid Expenses and Other Current Assets [Member]
Derivative Asset, Fair Value of Collateral	16,542	156
Prepaid Expenses and Other Current Assets [Member] | Ferrellgas, L.P. [Member]
Derivative Asset, Fair Value of Collateral	16,542	156
Other Current Liabilities [Member]
Derivative Liability, Fair Value of Collateral	15	0
Other Current Liabilities [Member] | Ferrellgas, L.P. [Member]
Derivative Liability, Fair Value of Collateral	15	0
Other Liabilities [Member]
Derivative Liability, Fair Value of Collateral	0	0
Other Liabilities [Member] | Ferrellgas, L.P. [Member]
Derivative Liability, Fair Value of Collateral	$ 0	$ 0