Debt - Security (Details) - USD ($) $ in Millions	Apr. 30, 2022	Jul. 31, 2021
Debt Instrument [Line Items]
Letters of credit outstanding	$ 90.8	$ 107.7
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Available borrowing capacity	259.2
Ferrellgas, L.P. [Member]
Debt Instrument [Line Items]
Letters of credit outstanding	90.8	$ 107.7
Available borrowing capacity	$ 259.2

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant