Derivative Instruments and Hedging Activities - AOCI Rollforward (Details) $ in Thousands, gal in Millions	3 Months Ended
Oct. 31, 2019 USD ($) gal	Oct. 31, 2018 USD ($)
Derivative [Line Items]
Partners' capital balance, beginning	$ (1,138,938)	$ (1,034,477)
Change in value of derivative	(13,627)
Change in value of derivative, pre-adoption		(8,154)
Reclassification of (gains) losses on derivatives to earnings, net	7,479
Reclassification of (gains) losses on derivatives to earnings, net, pre-adoption		(4,433)
Partners' capital balance, ending	(1,191,384)	(1,111,739)
Reclassification of net losses to earnings during next 12 months	19,300
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	4.5
Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member]
Derivative [Line Items]
Partners' capital balance, beginning	$ (14,756)
Partners' capital balance, ending	(20,904)
Accumulated Net Gain (Loss) from Cash Flow Hedges, pre-adoption
Derivative [Line Items]
Partners' capital balance, beginning		20,560
Partners' capital balance, ending		7,973
Ferrellgas, L.P. [Member]
Derivative [Line Items]
Partners' capital balance, beginning	(780,403)	(680,078)
Change in value of derivative	(13,627)
Change in value of derivative, pre-adoption		(8,154)
Reclassification of (gains) losses on derivatives to earnings, net	7,479
Reclassification of (gains) losses on derivatives to earnings, net, pre-adoption		(4,433)
Partners' capital balance, ending	(824,130)	(748,746)
Reclassification of net losses to earnings during next 12 months	19,300
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	4.5
Ferrellgas, L.P. [Member] \| Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member]
Derivative [Line Items]
Partners' capital balance, beginning	$ (14,756)
Partners' capital balance, ending	(20,904)
Ferrellgas, L.P. [Member] \| Accumulated Net Gain (Loss) from Cash Flow Hedges, pre-adoption
Derivative [Line Items]
Partners' capital balance, beginning		20,560
Partners' capital balance, ending		7,973
Commodity Derivatives Propane [Member] \| Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member]
Derivative [Line Items]
Change in value of derivative	(13,627)
Reclassification of (gains) losses on derivatives to earnings, net	7,479
Commodity Derivatives Propane [Member] \| Accumulated Net Gain (Loss) from Cash Flow Hedges, pre-adoption
Derivative [Line Items]
Change in value of derivative, pre-adoption		(8,154)
Reclassification of (gains) losses on derivatives to earnings, net, pre-adoption		(4,433)
Commodity Derivatives Propane [Member] \| Ferrellgas, L.P. [Member] \| Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member]
Derivative [Line Items]
Change in value of derivative	(13,627)
Reclassification of (gains) losses on derivatives to earnings, net	$ 7,479
Commodity Derivatives Propane [Member] \| Ferrellgas, L.P. [Member] \| Accumulated Net Gain (Loss) from Cash Flow Hedges, pre-adoption
Derivative [Line Items]
Change in value of derivative, pre-adoption		(8,154)
Reclassification of (gains) losses on derivatives to earnings, net, pre-adoption		$ (4,433)

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Nominal volume used to calculate payments on a derivative instrument.

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The amount of net gain (loss) reclassified into earnings in the period when cash flow hedge is discontinued because it is probable that the original forecasted transactions will not occur by the end of the original period or an additional two month time period.

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Amount, after tax and before reclassification, of gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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Amount, after tax, of reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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Amount after tax of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).

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Amount after tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Amount of partners' capital (deficit), including portions attributable to both the parent and noncontrolling interests. Excludes temporary equity and is sometimes called permanent equity.

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