Document And Entity Information - shares	6 Months Ended
	Jan. 31, 2021	Feb. 28, 2021
Document Information [Line Items]
Document Type	10-Q
Document Period End Date	Jan. 31, 2021
Document Transition Report	false
Entity Registrant Name	Ferrellgas Partners L P
Title of 12(b) Security	N/A
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		97,152,665
Current Fiscal Year End Date	--07-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Entity Central Index Key	0000922358
Amendment Flag	false
No Trading Symbol Flag	true
Ferrellgas Partners Finance Corp. [Member]
Document Information [Line Items]
Document Type	10-Q
Document Period End Date	Jan. 31, 2021
Entity Registrant Name	Ferrellgas Partners Finance Corp
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	true
Current Fiscal Year End Date	--07-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001012493
Amendment Flag	false
Ferrellgas, L.P. [Member]
Document Information [Line Items]
Document Type	10-Q
Document Period End Date	Jan. 31, 2021
Entity Registrant Name	Ferrellgas L P
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Current Fiscal Year End Date	--07-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Entity Central Index Key	0000922359
Amendment Flag	false
Ferrellgas Finance Corp. [Member]
Document Information [Line Items]
Document Type	10-Q
Document Period End Date	Jan. 31, 2021
Entity Registrant Name	Ferrellgas Finance Corp
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	true
Current Fiscal Year End Date	--07-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Entity Central Index Key	0000922360
Amendment Flag	false