Accounts And Notes Receivable, Net And Accounts Receivable Securitization Accounts And Notes Receivable, Net And Accounts Receivable Securitization (Consolidated Interest Coverage Ratio) (Details)	3 Months Ended	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2017	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017
current consolidated interest coverage ratio	199.00%	199.00%
Debt Instrument, Covenant Compliance		67.5
Debt Instrument, Covenant Description		8.7
Maximum [Member]
required consolidated interest coverage ratio	175.00%	175.00%	250.00%	175.00%	175.00%	175.00%
Minimum [Member]
required consolidated interest coverage ratio	250.00%	250.00%	250.00%	250.00%	250.00%	250.00%
Interest Coverage Covenant [Member]
Debt Instrument, Covenant Compliance		15.9
Debt Instrument, Covenant Description		27.8
Ferrellgas, L.P. [Member]
current consolidated interest coverage ratio	199.00%	199.00%
Debt Instrument, Covenant Compliance		67.5
Debt Instrument, Covenant Description		8.7
Ferrellgas, L.P. [Member] | Maximum [Member]
required consolidated interest coverage ratio	175.00%	175.00%	250.00%	175.00%	175.00%	175.00%
Ferrellgas, L.P. [Member] | Minimum [Member]
required consolidated interest coverage ratio	250.00%	250.00%	250.00%	250.00%	250.00%	250.00%
Ferrellgas, L.P. [Member] | Interest Coverage Covenant [Member]
Debt Instrument, Covenant Compliance	15.9
Debt Instrument, Covenant Description	27.8