Fair Value Measurements Fair Value Measurements (Narrative) (Details) - USD ($) $ in Millions	9 Months Ended
Apr. 30, 2018	Jul. 31, 2017
Notes Receivable, Fair Value Disclosure	$ 29.3
Increase (Decrease) in Notes Receivables	4.7
Long-term Debt, Fair Value	1,890.1	$ 1,966.6
Ferrellgas, L.P. [Member]
Notes Receivable, Fair Value Disclosure	29.3
Increase (Decrease) in Notes Receivables	4.7
Long-term Debt, Fair Value	$ 1,560.8	$ 1,645.3

The increase (decrease) during the reporting period of the amounts due from borrowers for outstanding secured or unsecured loans evidenced by a note.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

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- Definition

Fair value portion of an agreement for an unconditional promise by the maker to pay the holder a definite sum of money at a future date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.3(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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