Schedule I Parent Only Balance Sheets, Statements Of Earnings And Cash Flows (Statement Of Earnings) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Condensed Financial Statements, Captions [Line Items]
General and administrative expense													$ 49,617	$ 56,635	$ 77,238
Operating Income (Loss)													95,367	(534,244)	130,520
Interest expense													(152,485)	(137,937)	(100,396)
Other income (expense), net													1,474	110	(350)
Income tax expense													1,143	36	315
Net earnings (loss)	$ (56,249)	$ 6,691	$ 38,528	$ (43,471)	$ (668,142)	$ 18,918	$ 57,755	$ (80,566)	$ (59,333)	$ 36,220	$ 86,371	$ (33,169)	(54,501)	(672,035)	30,089
Parent Company [Member]
Condensed Financial Statements, Captions [Line Items]
Equity in earnings (loss) of Ferrellgas, L.P.													(28,765)	(648,771)	45,958
General and administrative expense													139	520	104
Operating Income (Loss)													(28,904)	(649,291)	45,854
Interest expense													(25,297)	(16,119)	(16,169)
Income tax expense													6	5	(69)
Other income													0	0	4
Net earnings (loss)													$ (54,207)	$ (665,415)	$ 29,620