Supplemental Financial Statement Information (Other Current Liabilities) (Details) - USD ($) $ in Thousands	Jan. 31, 2018	Jul. 31, 2017
Accrued interest	$ 18,975	$ 18,671
Customer deposits and advances	24,676	25,541
Other	96,859	82,012
Other current liabilities	140,510	126,224
Ferrellgas, L.P. [Member]
Accrued interest	15,041	14,737
Customer deposits and advances	24,676	25,541
Other	96,874	81,738
Other current liabilities	$ 136,591	$ 122,016