Transactions With Related Parties (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Apr. 30, 2020 USD ($) employee	Apr. 30, 2019 USD ($)	Apr. 30, 2020 USD ($) employee	Apr. 30, 2019 USD ($)
Related Party Transaction [Line Items]
Entity Number of Employees | employee	0		0
Ferrellgas, L.P. [Member]
Related Party Transaction [Line Items]
Entity Number of Employees | employee	0		0
Ferrellgas Finance Corp. [Member]
Related Party Transaction [Line Items]
Entity Number of Employees | employee	0		0
Ferrellgas Partners Finance Corp. [Member]
Related Party Transaction [Line Items]
Entity Number of Employees | employee	0		0
Ferrellgas Inc., General Partner [Member] | Operating Expense [Member]
Related Party Transaction [Line Items]
Expenses reimbursed to related party | $	$ 67,241	$ 64,030	$ 203,796	$ 193,258
Ferrellgas Inc., General Partner [Member] | Operating Expense [Member] | Ferrellgas, L.P. [Member]
Related Party Transaction [Line Items]
Expenses reimbursed to related party | $	67,241	64,030	203,796	193,258
Ferrellgas Inc., General Partner [Member] | General and Administrative Expense [Member]
Related Party Transaction [Line Items]
Expenses reimbursed to related party | $	7,705	5,872	21,668	19,196
Ferrellgas Inc., General Partner [Member] | General and Administrative Expense [Member] | Ferrellgas, L.P. [Member]
Related Party Transaction [Line Items]
Expenses reimbursed to related party | $	$ 7,705	$ 5,872	$ 21,668	$ 19,196