Supplemental Financial Statement Information (Shipping And Handling Expenses) (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2017	Oct. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	$ 50,495	$ 49,502
Ferrellgas, L.P. [Member]
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	50,495	49,502
Operating Expense [Member]
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	43,314	41,810
Operating Expense [Member] | Ferrellgas, L.P. [Member]
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	43,314	41,810
Depreciation And Amortization Expense [Member]
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	1,112	1,026
Depreciation And Amortization Expense [Member] | Ferrellgas, L.P. [Member]
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	1,112	1,026
Equipment Lease Expense [Member]
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	6,069	6,666
Equipment Lease Expense [Member] | Ferrellgas, L.P. [Member]
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	$ 6,069	$ 6,666