Fair Value Measurements Fair Value Measurements (Fair Value Inputs, Liabilities, Quantitative Information) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Oct. 31, 2014	Jul. 31, 2014
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	$ 4,600	$ 6,400
Fair Value Measurements, Valuation Techniques	Discounted cash flow
Weighted Average of Unobservable Input	20.00%
Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Range of Unobservable Inputs	10.00%
Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Range of Unobservable Inputs	75.00%
Ferrellgas, L.P. [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	$ 4,600	$ 6,400
Fair Value Measurements, Valuation Techniques	Discounted cash flow
Weighted Average of Unobservable Input	20.00%
Ferrellgas, L.P. [Member] | Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Range of Unobservable Inputs	10.00%
Ferrellgas, L.P. [Member] | Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Range of Unobservable Inputs	75.00%