Supplemental Financial Statement Information - Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Oct. 31, 2019	Oct. 31, 2018
Supplemental Financial Statement Information [Line Items]
Interest paid (refunded)	$ 8,284	$ 8,930
Income taxes paid (refunded)		2
Noncash Investing and Financing Items [Abstract]
Liabilities incurred in connection with acquisitions	520	1,096
Change in accruals for property, plant and equipment additions	(43)	(315)
Right-of-use assets arising from operating and finance lease liabilities	17,177
Ferrellgas, L.P. [Member]
Supplemental Financial Statement Information [Line Items]
Interest paid (refunded)	8,284	8,930
Income taxes paid (refunded)	0	(5)
Noncash Investing and Financing Items [Abstract]
Liabilities incurred in connection with acquisitions	520	1,096
Change in accruals for property, plant and equipment additions	(43)	$ (315)
Right-of-use assets arising from operating and finance lease liabilities	$ 17,177