Derivatives (Narrative) (Details) (USD $)	3 Months Ended
	Oct. 31, 2011	Oct. 31, 2010
Gain (loss) recognized in earnings related to hedge ineffectiveness	$ 0	$ 0
Reclassification of net gain to earnings during next 12 months	800,000
Reclassification of gain (loss) to earnings from discontinuance of cash flow hedges	0	0
Number of barrels of propane entered into as cash flow hedges	700,000
Percentage of top four companies cash flow hedge settled	90.00%	95.00%
Ferrellgas, L.P. And Subsidiaries [Member]
Gain (loss) recognized in earnings related to hedge ineffectiveness	0	0
Reclassification of net gain to earnings during next 12 months	800,000
Reclassification of gain (loss) to earnings from discontinuance of cash flow hedges	$ 0	$ 0
Number of barrels of propane entered into as cash flow hedges	700,000
Percentage of top four companies cash flow hedge settled	90.00%	95.00%