Fair Value Measurements Fair Value Measurements (Sensitivity of Unobservable Inputs) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Apr. 30, 2015
5% increase, WACC [Member]
Sensitivity of Unobservable Inputs [Line Items]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	$ (10)
5% decrease, WACC [Member]
Sensitivity of Unobservable Inputs [Line Items]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	100
10% increase, earnings forecast [Member]
Sensitivity of Unobservable Inputs [Line Items]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	180
10% decrease, earnings forecast [Member]
Sensitivity of Unobservable Inputs [Line Items]
Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings	(100)
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	(10)
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	100
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	180
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	$ (100)