Derivative Instruments and Hedging Activities (Changes in Derivative Value Effect on Other Comprehensive Income Loss) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2017	Apr. 30, 2016	Jul. 31, 2016	Jul. 31, 2015
Beginning balance	$ 6,086		$ 6,086		$ (10,468)
Change in value of risk management derivatives	(6,496)	$ 14,681	13,904	$ 3,561
Reclassification of gains and losses on commodity hedges to cost of product sold - propane and other gas liquids sales	(1,933)	6,138	2,819	22,931
Ending balance	6,086		6,086
Ferrellgas, L.P. [Member]
Beginning balance	6,163		6,163		(10,560)
Change in value of risk management derivatives	(6,496)	14,681	13,904	3,561
Reclassification of gains and losses on commodity hedges to cost of product sold - propane and other gas liquids sales	(1,933)	6,138	2,819	22,931
Ending balance	6,163		6,163
Propane commodity derivatives [Member]
Change in value of risk management derivatives	(6,642)	14,998	12,930	5,823
Reclassification of gains and losses on commodity hedges to cost of product sold - propane and other gas liquids sales			1,112	20,729
Propane commodity derivatives [Member] \| Ferrellgas, L.P. [Member]
Change in value of risk management derivatives	(6,642)	14,998	12,930	5,823
Reclassification of gains and losses on commodity hedges to cost of product sold - propane and other gas liquids sales			1,112	20,729
Interest Rate Swap [Member]
Change in value of risk management derivatives	146	(317)	974	(2,262)
Derivative, Net Hedge Ineffectiveness Gain (Loss)			1,707	2,202
Interest Rate Swap [Member] \| Ferrellgas, L.P. [Member]
Change in value of risk management derivatives	146	(317)	974	(2,262)
Derivative, Net Hedge Ineffectiveness Gain (Loss)			1,707	2,202
Derivative [Member]
Beginning balance	6,908	(12,414)	6,908	(12,414)	(9,815)	$ (38,906)
Ending balance	6,908	(12,414)	6,908	(12,414)
Derivative [Member] \| Ferrellgas, L.P. [Member]
Beginning balance	6,908	(12,414)	6,908	(12,414)	$ (9,815)	$ (38,906)
Ending balance	$ 6,908	$ (12,414)	$ 6,908	$ (12,414)

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=66004124&loc=d3e637-108580

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=66004124&loc=d3e681-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=66004124&loc=SL7669686-108580

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624177-113959

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The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

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Amount of gain (loss) from the ineffectiveness of the hedge.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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