Derivative Instruments and Hedging Activities - AOCI Rollforward (Details) gal in Millions	3 Months Ended		6 Months Ended
	Jan. 31, 2021 USD ($)	Jan. 31, 2020 USD ($)	Jan. 31, 2021 USD ($) gal	Jan. 31, 2020 USD ($)
Derivative [Line Items]
Partners' capital balance, beginning	$ (1,246,096,000)	$ (1,191,384,000)	$ (1,208,268,000)	$ (1,138,938,000)
Change in value of derivative	36,957,000	(11,212,000)	42,724,000	(24,839,000)
Reclassification of (gains) losses on derivatives to earnings, net	(8,441,000)	8,766,000	(6,291,000)	16,245,000
Partners' capital balance, ending	(1,152,827,000)	(1,144,675,000)	(1,152,827,000)	(1,144,675,000)
Reclassification of net gain to earnings during next 12 months			32,100,000
Gain (loss) on discontinuation of cash flow hedge due to forecasted transaction probable of not occurring, net			$ 0	0
Number of barrels of propane covered by cash flow hedges | gal			3.8
Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member]
Derivative [Line Items]
Partners' capital balance, beginning			$ (2,313,000)	(14,756,000)
Change in value of derivative			42,724,000	(24,839,000)
Reclassification of (gains) losses on derivatives to earnings, net			(6,291,000)	16,245,000
Partners' capital balance, ending	34,120,000	(23,350,000)	34,120,000	(23,350,000)
Ferrellgas, L.P. [Member]
Derivative [Line Items]
Partners' capital balance, beginning	(862,117,000)	(824,130,000)	(831,991,000)	(780,403,000)
Change in value of derivative	36,957,000	(11,212,000)	42,724,000	(24,839,000)
Reclassification of (gains) losses on derivatives to earnings, net	(8,441,000)	8,766,000	(6,291,000)	16,245,000
Partners' capital balance, ending	(761,089,000)	(783,852,000)	(761,089,000)	(783,852,000)
Reclassification of net gain to earnings during next 12 months			32,100,000
Gain (loss) on discontinuation of cash flow hedge due to forecasted transaction probable of not occurring, net			$ 0	0
Number of barrels of propane covered by cash flow hedges | gal			3.8
Ferrellgas, L.P. [Member] | Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member]
Derivative [Line Items]
Partners' capital balance, beginning			$ (2,313,000)	(14,756,000)
Change in value of derivative			42,724,000	(24,839,000)
Reclassification of (gains) losses on derivatives to earnings, net			(6,291,000)	16,245,000
Partners' capital balance, ending	$ 34,120,000	$ (23,350,000)	$ 34,120,000	$ (23,350,000)