Transactions With Related Parties (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2020 USD ($) employee	Jan. 31, 2019 USD ($)	Jan. 31, 2020 USD ($) employee	Jan. 31, 2019 USD ($)
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 | $	$ 73,084	$ 69,285	$ 136,555	$ 129,243
Ferrellgas Inc., General Partner [Member] | Operating Expense [Member] | Ferrellgas, L.P. [Member]
Related Party Transaction [Line Items]
Expenses reimbursed to related party | $	73,084	69,285	136,555	129,243
Ferrellgas Inc., General Partner [Member] | General and Administrative Expense [Member]
Related Party Transaction [Line Items]
Expenses reimbursed to related party | $	7,476	7,197	13,963	13,309
Ferrellgas Inc., General Partner [Member] | General and Administrative Expense [Member] | Ferrellgas, L.P. [Member]
Related Party Transaction [Line Items]
Expenses reimbursed to related party | $	$ 7,476	$ 7,197	$ 13,963	$ 13,309