Supplemental Financial Statement Information (Shipping And Handling Expenses) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Jan. 31, 2018	Jan. 31, 2017
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	$ 62,032	$ 54,805	$ 112,527	$ 104,223
Ferrellgas, L.P. [Member]
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	62,032	54,805	112,527	104,223
Operating Expense [Member]
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	54,613	47,157	97,928	88,883
Operating Expense [Member] | Ferrellgas, L.P. [Member]
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	54,613	47,157	97,928	88,883
Depreciation And Amortization Expense [Member]
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	1,123	996	2,235	2,022
Depreciation And Amortization Expense [Member] | Ferrellgas, L.P. [Member]
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	1,123	996	2,235	2,022
Equipment Lease Expense [Member]
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	6,296	6,652	12,364	13,318
Equipment Lease Expense [Member] | Ferrellgas, L.P. [Member]
Condensed Financial Statements, Captions [Line Items]
Shipping and handling expenses	$ 6,296	$ 6,652	$ 12,364	$ 13,318