Transactions With Related Parties (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2019 USD ($) employee	Jan. 31, 2018 USD ($)	Jan. 31, 2019 USD ($) employee	Jan. 31, 2018 USD ($)
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
Operating Expense [Member]
Related Party Transaction [Line Items]
Expenses reimbursed to related party	$ 69,285	$ 65,291
General and Administrative Expense [Member]
Related Party Transaction [Line Items]
Expenses reimbursed to related party	7,197	8,422
Ferrellgas Inc., General Partner [Member] | Operating Expense [Member]
Related Party Transaction [Line Items]
Expenses reimbursed to related party			$ 129,243	$ 122,642
Ferrellgas Inc., General Partner [Member] | Operating Expense [Member] | Ferrellgas, L.P. [Member]
Related Party Transaction [Line Items]
Expenses reimbursed to related party	69,285	65,291	129,243	122,642
Ferrellgas Inc., General Partner [Member] | General and Administrative Expense [Member]
Related Party Transaction [Line Items]
Expenses reimbursed to related party			13,309	15,930
Ferrellgas Inc., General Partner [Member] | General and Administrative Expense [Member] | Ferrellgas, L.P. [Member]
Related Party Transaction [Line Items]
Expenses reimbursed to related party	$ 7,197	$ 8,422	$ 13,309	$ 15,930