Leases - Lease Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2021	Jan. 31, 2020
Lease, Cost [Abstract]
Operating lease expense	$ 8,696	$ 10,841	$ 17,729	$ 20,844
Short-term expense	1,996	2,153	4,269	4,217
Variable lease expense	1,147	824	2,281	2,232
Total finance lease expense	3,152	753	6,262	835
Total lease expense	14,991	14,571	30,541	28,128
Midstream Operations [Member]
Lease, Cost [Abstract]
Total lease expense	100	100	200	200
Operating expenses - personnel, vehicle, plant and other
Lease, Cost [Abstract]
Operating lease expense	1,497	1,664	3,280	3,405
Short-term expense	1,873	2,012	3,905	3,966
Variable lease expense	798	671	1,544	1,346
Operating expense - equipment lease expense
Lease, Cost [Abstract]
Operating lease expense	6,513	8,156	12,955	15,763
Variable lease expense	349	153	737	886
Cost of Sales [Member]
Lease, Cost [Abstract]
Operating lease expense	492	324	1,018	713
General and Administrative Expense [Member]
Lease, Cost [Abstract]
Operating lease expense	194	697	476	963
Short-term expense	123	141	364	251
Depreciation And Amortization Expense [Member]
Lease, Cost [Abstract]
Amortization of leased assets	2,189	435	4,354	475
Interest Expense [Member]
Lease, Cost [Abstract]
Interest on lease liabilities	963	318	1,908	360
Ferrellgas, L.P. [Member]
Lease, Cost [Abstract]
Operating lease expense	8,696	10,841	17,729	20,844
Short-term expense	1,996	2,153	4,269	4,217
Variable lease expense	1,147	824	2,281	2,232
Total finance lease expense	3,152	753	6,262	835
Total lease expense	14,991	14,571	30,541	28,128
Ferrellgas, L.P. [Member] | Midstream Operations [Member]
Lease, Cost [Abstract]
Total lease expense	100	100	200	200
Ferrellgas, L.P. [Member] | Operating expenses - personnel, vehicle, plant and other
Lease, Cost [Abstract]
Operating lease expense	1,497	1,664	3,280	3,405
Short-term expense	1,873	2,012	3,905	3,966
Variable lease expense	798	671	1,544	1,346
Ferrellgas, L.P. [Member] | Operating expense - equipment lease expense
Lease, Cost [Abstract]
Operating lease expense	6,513	8,156	12,955	15,763
Variable lease expense	349	153	737	886
Ferrellgas, L.P. [Member] | Cost of Sales [Member]
Lease, Cost [Abstract]
Operating lease expense	492	324	1,018	713
Ferrellgas, L.P. [Member] | General and Administrative Expense [Member]
Lease, Cost [Abstract]
Operating lease expense	194	697	476	963
Short-term expense	123	141	364	251
Ferrellgas, L.P. [Member] | Depreciation And Amortization Expense [Member]
Lease, Cost [Abstract]
Amortization of leased assets	2,189	435	4,354	475
Ferrellgas, L.P. [Member] | Interest Expense [Member]
Lease, Cost [Abstract]
Interest on lease liabilities	$ 963	$ 318	$ 1,908	$ 360