Derivative Instruments and Hedging Activities - Effect on Earnings (Details) - Interest Rate Swap [Member] - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Apr. 30, 2018	Apr. 30, 2018
Derivative [Line Items]
Amount of Gain Recognized	$ 40	$ 266
Amount of Interest Expense Recognized	(2,275)	(6,825)
Ferrellgas, L.P. [Member]
Derivative [Line Items]
Amount of Gain Recognized	40	266
Amount of Interest Expense Recognized	$ (2,275)	$ (6,825)

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5618551-113959

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Amount of the cost of borrowed funds accounted for as interest expense for debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6036836-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227

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