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Quarterly Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Interim Period, Costs Not Allocable [Line Items]
Reporting Unit, Name of Segment [Extensible List]					Propane and related equipment sales									Propane and related equipment sales
Goodwill, Impairment Loss														$ 10,000
Revenues	$ 279,081	$ 479,625	$ 573,377	$ 352,309	$ 347,521	$ 515,810	$ 755,156	$ 454,655	$ 433,376	$ 538,109	$ 579,250	$ 379,542	$ 1,684,392	2,073,142	$ 1,930,277
Net loss	(71,672)	20,760	43,875	(57,508)	(217,797)	11,062	(1,774)	(48,316)	(56,249)	6,691	38,528	(43,471)	(64,545)	(256,825)	(54,501)
Net earnings (loss)	(71,037)	20,461	43,344	(57,015)	(215,684)	10,861	(1,843)	(47,915)	(55,768)	6,536	38,098	(43,073)	(64,247)	(254,581)	(54,207)
Common unitholders' interest in net earnings (loss)	$ (70,327)	$ 20,256	$ 42,911	$ (56,445)	$ (213,527)	$ 10,752	$ (1,824)	$ (47,436)	$ (55,210)	$ 6,470	$ 37,717	$ (42,462)	$ (63,605)	$ (252,035)	$ (53,665)
Basic and diluted net loss per common unit	$ (0.72)	$ 0.21	$ 0.44	$ (0.58)	$ (2.20)	$ 0.11	$ (0.02)	$ (0.49)	$ (0.57)	$ 0.07	$ 0.39	$ (0.44)	$ (0.65)	$ (2.59)	$ (0.55)
Asset impairments							$ 10,000						$ 0	$ 10,005	$ 0
Ferrellgas, L.P. [Member]
Interim Period, Costs Not Allocable [Line Items]
Goodwill, Impairment Loss														10,000
Revenues	$ 279,081	$ 479,625	$ 573,377	$ 352,309	$ 347,521	$ 515,810	755,156	$ 454,655	$ 433,376	$ 538,109	$ 579,250	$ 379,542	1,684,392	2,073,142	1,930,277
Net loss	(62,874)	29,554	52,617	(48,814)	(209,134)	19,840	6,847	(39,699)	(47,614)	15,395	42,600	(39,440)	(29,517)	(222,146)	(29,059)
Net earnings (loss)													(29,517)	(222,146)	(29,059)
Asset impairments													0	10,005	0
Propane and related equipment sales
Interim Period, Costs Not Allocable [Line Items]
Goodwill, Impairment Loss														10,005
Revenues													1,684,392	1,790,823	1,463,574
Gross margin from propane and other gas liquids sales (a)	127,764	209,167	238,581	130,830	126,115	190,883	229,321	123,243	126,774	171,950	202,346	123,187
Propane and related equipment sales \| Ferrellgas, L.P. [Member]
Interim Period, Costs Not Allocable [Line Items]
Goodwill, Impairment Loss														10,005
Revenues													$ 1,684,392	$ 1,790,823	$ 1,463,574
Gross margin from propane and other gas liquids sales (a)	$ 127,764	$ 209,167	$ 238,581	$ 130,830	126,115	190,883	229,321	123,243	126,774	171,950	202,346	123,187
Asset impairments							10,000
Consolidated Midstream Operations [Member]
Interim Period, Costs Not Allocable [Line Items]
Gross margin from propane and other gas liquids sales (a)					(4,161)	8,077	10,209	12,635	6,190	7,909	9,763	13,402
Consolidated Midstream Operations [Member] \| Ferrellgas, L.P. [Member]
Interim Period, Costs Not Allocable [Line Items]
Gross margin from propane and other gas liquids sales (a)					$ (4,161)	$ 8,077	$ 10,209	$ 12,635	$ 6,190	$ 7,909	$ 9,763	$ 13,402