Leases - Lease Expenses (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Apr. 30, 2020	Apr. 30, 2020
Lease, Cost [Abstract]
Operating lease expense	$ 10,446	$ 31,290
Short-term expense	1,635	5,852
Variable lease expense	1,224	3,456
Total finance lease expense	937	1,772
Total lease expense	14,242	42,370
Operating expenses - personnel, vehicle, plant and other
Lease, Cost [Abstract]
Operating lease expense	1,946	5,351
Short-term expense	1,512	5,478
Variable lease expense	751	2,097
Operating expense - equipment lease expense
Lease, Cost [Abstract]
Operating lease expense	7,602	23,365
Variable lease expense	473	1,359
Cost of Sales [Member]
Lease, Cost [Abstract]
Operating lease expense	370	1,083
General and Administrative Expense [Member]
Lease, Cost [Abstract]
Operating lease expense	528	1,491
Short-term expense	123	374
Depreciation And Amortization Expense [Member]
Lease, Cost [Abstract]
Amortization of leased assets	754	1,229
Interest Expense [Member]
Lease, Cost [Abstract]
Interest on lease liabilities	183	543
Ferrellgas, L.P. [Member]
Lease, Cost [Abstract]
Operating lease expense	10,446	31,290
Short-term expense	1,635	5,852
Variable lease expense	1,224	3,456
Total finance lease expense	937	1,772
Total lease expense	14,242	42,370
Ferrellgas, L.P. [Member] | Operating expenses - personnel, vehicle, plant and other
Lease, Cost [Abstract]
Operating lease expense	1,946	5,351
Short-term expense	1,512	5,478
Variable lease expense	751	2,097
Ferrellgas, L.P. [Member] | Operating expense - equipment lease expense
Lease, Cost [Abstract]
Operating lease expense	7,602	23,365
Variable lease expense	473	1,359
Ferrellgas, L.P. [Member] | Cost of Sales [Member]
Lease, Cost [Abstract]
Operating lease expense	370	1,083
Ferrellgas, L.P. [Member] | General and Administrative Expense [Member]
Lease, Cost [Abstract]
Operating lease expense	528	1,491
Short-term expense	123	374
Ferrellgas, L.P. [Member] | Depreciation And Amortization Expense [Member]
Lease, Cost [Abstract]
Amortization of leased assets	754	1,229
Ferrellgas, L.P. [Member] | Interest Expense [Member]
Lease, Cost [Abstract]
Interest on lease liabilities	$ 183	$ 543