Segment Reporting Segment Reporting (Reconciliation of Assets from Segment to Consolidated) (Details) - USD ($) $ in Thousands	Apr. 30, 2018	Jul. 31, 2017
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 1,532,576	$ 1,609,969
Propane and related equipment sales [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	1,274,360	1,194,905
Midstream Operations [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	244,523	399,356
Corporate Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	13,693	15,708
Ferrellgas, L.P. [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	1,532,537	1,609,948
Ferrellgas, L.P. [Member] | Propane and related equipment sales [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	1,274,360	1,194,905
Ferrellgas, L.P. [Member] | Midstream Operations [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	244,523	399,356
Ferrellgas, L.P. [Member] | Corporate Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 13,654	$ 15,687