Supplemental Financial Statement Information - Cash Flow Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Apr. 30, 2019	Apr. 30, 2018
Supplemental Financial Statement Information [Line Items]
Interest paid (refunded)	$ 93,465	$ 85,171
Income taxes paid (refunded)	21	(458)
Noncash Investing and Financing Items [Abstract]
Liabilities incurred in connection with acquisitions	1,174	1,508
Change in accruals for property, plant and equipment additions	1,202	386
Ferrellgas, L.P. [Member]
Supplemental Financial Statement Information [Line Items]
Interest paid (refunded)	78,069	69,775
Income taxes paid (refunded)	(9)	(479)
Noncash Investing and Financing Items [Abstract]
Liabilities incurred in connection with acquisitions	1,174	1,508
Change in accruals for property, plant and equipment additions	$ 1,202	$ 386