Accounts And Notes Receivable, Net And Accounts Receivable Securitization Accounts And Notes Receivcable, Net And Accounts Receivable Securitization (Maximum Leverage Ratio) (Details) - Maximum [Member]	3 Months Ended
	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018
required total leverage ratio	550.00%	775.00%	775.00%
Ferrellgas, L.P. [Member]
required total leverage ratio	550.00%	775.00%	775.00%