Accounts And Notes Receivable, Net And Accounts Receivable Securitization (Narrative) (Details) - USD ($)	Jan. 31, 2019	Jul. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable pledged as collateral	$ 201,717,000	$ 120,079,000
Ferrellgas, L.P. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable pledged as collateral	201,717,000	120,079,000
Secured Credit Facility [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collateralized notes payable	140,000,000	58,000,000
Capacity to receive additional proceeds	$ 0	$ 0
Weighted average interest rate of debt	5.30%	5.20%
Secured Credit Facility [Member] | Ferrellgas, L.P. [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Collateralized notes payable	$ 140,000,000	$ 58,000,000
Capacity to receive additional proceeds	$ 0	$ 0
Weighted average interest rate of debt	5.30%	5.20%