Consolidated Statements Of Partners' Capital (Deficit) - 6 months ended Jan. 31, 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	7,993	0	7,914	79	7,833	81	7,993	0	7,914	79
Distributions	(19,984)	0	(19,627)	(357)	(19,431)	(196)	(35,380)	0	(35,023)	(357)
Net loss	(50,090)	0	(49,758)	(332)	$ (49,260)	$ (498)	(32,852)	0	(32,520)	(332)
Other comprehensive income (loss)	9,829	9,731	9,731	98			9,829	9,829	0	0
Partners' capital balance (in units) at Jan. 31, 2018					97,152,700	989,900
Partners' capital balance at Jan. 31, 2018	$ (809,762)	$ 24,332	$ (805,318)	$ (4,444)	$ (762,046)	$ (67,604)	$ (457,208)	$ 24,593	$ (477,096)	$ (4,705)