Derivative Instruments and Hedging Activities (Narrative) (Details) (USD $)	12 Months Ended
	Jul. 31, 2012	Jul. 31, 2011
Gain (loss) recognized in earnings related to hedge ineffectiveness	$ 0	$ 0
Reclassification of net gain to earnings during next 12 months	9,600,000
Reclassification of gain (loss) to earnings from discontinuance of cash flow hedges	0	0
Number of barrels of propane covered by cash flow hedges	1,400,000
Derivative amount of credit risk	800,000
Derivative, Net Liability Position, Aggregate Fair Value	4,700,000
Collateral Already Posted, Aggregate Fair Value	4,300,000
Additional Collateral, Aggregate Fair Value	0
Ferrellgas, L.P. [Member]
Gain (loss) recognized in earnings related to hedge ineffectiveness	0	0
Reclassification of net gain to earnings during next 12 months	9,600,000
Reclassification of gain (loss) to earnings from discontinuance of cash flow hedges	0	0
Number of barrels of propane covered by cash flow hedges	1,400,000
Derivative amount of credit risk	800,000
Derivative, Net Liability Position, Aggregate Fair Value	4,700,000
Collateral Already Posted, Aggregate Fair Value	4,300,000
Additional Collateral, Aggregate Fair Value	$ 0