Fair Value Measurements Fair Value Measurements (Sensitivity of Unobservable Inputs) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Jul. 31, 2014
5% increase, WACC [Member]
Sensitivity of Unobservable Inputs [Line Items]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	$ (470)
5% decrease, WACC [Member]
Sensitivity of Unobservable Inputs [Line Items]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	400
10% increase, earnings forecast [Member]
Sensitivity of Unobservable Inputs [Line Items]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	840
10% decrease, earnings forecast [Member]
Sensitivity of Unobservable Inputs [Line Items]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	(1,010)
Ferrellgas, L.P. [Member] | 5% increase, WACC [Member]
Sensitivity of Unobservable Inputs [Line Items]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	(470)
Ferrellgas, L.P. [Member] | 5% decrease, WACC [Member]
Sensitivity of Unobservable Inputs [Line Items]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	400
Ferrellgas, L.P. [Member] | 10% increase, earnings forecast [Member]
Sensitivity of Unobservable Inputs [Line Items]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	840
Ferrellgas, L.P. [Member] | 10% decrease, earnings forecast [Member]
Sensitivity of Unobservable Inputs [Line Items]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	$ (1,010)