Segment Reporting - Assets (Details) - USD ($) $ in Thousands	Jul. 31, 2019	Jul. 31, 2018
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 1,262,959	$ 1,363,281
Propane and related equipment sales
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,223,790	1,196,084
Corporate and other
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	39,169	167,197
Ferrellgas, L.P. [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,262,833	1,363,246
Ferrellgas, L.P. [Member] | Propane and related equipment sales
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	1,223,790	1,196,084
Ferrellgas, L.P. [Member] | Corporate and other
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 39,043	$ 167,162