Derivative Instruments and Hedging Activities (Fair Value of Financial Derivatives Balance Sheet Locations) (Details) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2013	Jul. 31, 2012
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management assets	$ 2,532	$ 1,049
Interest Rate Derivative Assets, at Fair Value	3,783	7,784
Derivative Asset, Fair Value, Gross Asset	6,315	8,833
Derivatives - Price risk management liabilities	907	12,069
Interest Rate Derivative Liabilities, at Fair Value	4,998	1,778
Derivative Liability, Fair Value, Gross Liability	5,905	13,847
Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management assets	2,532	1,049
Interest Rate Derivative Assets, at Fair Value	3,783	7,784
Derivative Asset, Fair Value, Gross Asset	6,315	8,833
Derivatives - Price risk management liabilities	907	12,069
Interest Rate Derivative Liabilities, at Fair Value	4,998	1,778
Derivative Liability, Fair Value, Gross Liability	5,905	13,847
Prepaid Expenses And Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management assets	1,400	1,049
Interest Rate Derivative Assets, at Fair Value	3,341	3,346
Prepaid Expenses And Other Current Assets [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management assets	1,400	1,049
Interest Rate Derivative Assets, at Fair Value	3,341	3,346
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management liabilities	569	12,069
Interest Rate Derivative Liabilities, at Fair Value	0	0
Other Current Liabilities [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management liabilities	569	12,069
Interest Rate Derivative Liabilities, at Fair Value	0	0
Other Assets, Net [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management assets	1,132
Interest Rate Derivative Assets, at Fair Value	442	4,438
Other Assets, Net [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management assets	1,132
Interest Rate Derivative Assets, at Fair Value	442	4,438
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management liabilities	338
Interest Rate Derivative Liabilities, at Fair Value	4,998	1,778
Other Liabilities [Member] | Ferrellgas, L.P. [Member]
Derivatives, Fair Value [Line Items]
Derivatives - Price risk management liabilities	338
Interest Rate Derivative Liabilities, at Fair Value	$ 4,998	$ 1,778