Consolidated Statements Of Partners' Capital (Deficit) - 9 months ended Apr. 30, 2018 - USD ($) $ in Thousands	Total	Accumulated Other Comprehensive Income (Loss)	Total Ferrellgas Partners, L.P. Partners' Capital (Deficit) [Member]	Noncontrolling Interest [Member]	Common Unitholders [Member]	General Partner Unitholder [Member]	Ferrellgas, L.P. [Member]	Ferrellgas, L.P. [Member] Accumulated Other Comprehensive Income (Loss)	Ferrellgas, L.P. [Member] Common Unitholders [Member]	Ferrellgas, L.P. [Member] General Partner Unitholder [Member]
Partners' capital balance (in units) at Jul. 31, 2017					97,152,700	989,900
Partners' capital balance at Jul. 31, 2017	$ (757,510)	$ 14,601	$ (753,578)	$ (3,932)	$ (701,188)	$ (66,991)	$ (406,798)	$ 14,764	$ (417,467)	$ (4,095)
Increase (Decrease) in Partners' Capital [Roll Forward]
Contributions in connection with non-cash ESOP and stock and unit-based compensation charges	10,731	0	10,623	108	10,517	106	10,731	0	10,623	108
Distributions	(29,899)	0	(29,440)	(459)	(29,146)	(294)	(45,495)	0	(45,036)	(459)
Net loss	(39,028)	0	(38,897)	(131)	$ (38,508)	$ (389)	(13,012)	0	(12,881)	(131)
Other comprehensive income (loss)	3,102	3,071	3,071	31			3,102	3,102	0	0
Partners' capital balance (in units) at Apr. 30, 2018					97,152,700	989,900
Partners' capital balance at Apr. 30, 2018	$ (812,604)	$ 17,672	$ (808,221)	$ (4,383)	$ (758,325)	$ (67,568)	$ (451,472)	$ 17,866	$ (464,761)	$ (4,577)