Consolidated Statements Of Partners' Deficit - USD ($)	3 Months Ended						12 Months Ended
	Jul. 31, 2019	Oct. 31, 2018	Jul. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Oct. 31, 2016	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
Increase (Decrease) in Partners' Capital [Roll Forward]
Partners' capital balance, beginning		$ (1,034,477,000)		$ (757,510,000)		$ (651,780,000)	$ (1,034,477,000)	$ (757,510,000)	$ (651,780,000)
Contributions in connection with non-cash ESOP and stock and unit-based compensation charges							5,693,000	13,859,000	18,386,000
Distributions							(10,229,000)	(39,970,000)	(80,783,000)
Common unit repurchases									(15,851,000)
Other contributions									1,695,000
Net loss	$ (71,672,000)	(57,508,000)	$ (217,797,000)	(48,316,000)	$ (56,249,000)	(43,471,000)	(64,545,000)	(256,825,000)	(54,501,000)
Other comprehensive income (loss)							(35,380,000)	5,969,000	25,324,000
Partners' capital balance, ending	(1,138,938,000)		(1,034,477,000)		(757,510,000)		(1,138,938,000)	(1,034,477,000)	(757,510,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(71,672,000)	(57,508,000)	(217,797,000)	(48,316,000)	(56,249,000)	(43,471,000)	(64,545,000)	(256,825,000)	(54,501,000)
Other contributions									1,695,000
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Partners' Capital [Roll Forward]
Partners' capital balance, beginning		20,510,000		14,601,000		(10,468,000)	20,510,000	14,601,000	(10,468,000)
Other comprehensive income (loss)							(35,022,000)	5,909,000	25,069,000
Partners' capital balance, ending	(14,512,000)		20,510,000		14,601,000		(14,512,000)	20,510,000	14,601,000
Parent [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Partners' capital balance, beginning		(1,027,785,000)		(753,578,000)		(647,057,000)	(1,027,785,000)	(753,578,000)	(647,057,000)
Contributions in connection with non-cash ESOP and stock and unit-based compensation charges							5,635,000	13,719,000	18,201,000
Distributions							(9,814,000)	(39,254,000)	(79,733,000)
Common unit repurchases									(15,851,000)
Other contributions									0
Net loss							(64,247,000)	(254,581,000)	(54,207,000)
Other comprehensive income (loss)							(35,022,000)	5,909,000	25,069,000
Partners' capital balance, ending	(1,131,233,000)		(1,027,785,000)		(753,578,000)		(1,131,233,000)	(1,027,785,000)	(753,578,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss							(64,247,000)	(254,581,000)	(54,207,000)
Other contributions									0
Non-Controlling Interest [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Partners' capital balance, beginning		$ (6,692,000)		$ (3,932,000)		$ (4,723,000)	(6,692,000)	(3,932,000)	(4,723,000)
Contributions in connection with non-cash ESOP and stock and unit-based compensation charges							58,000	140,000	185,000
Distributions							(415,000)	(716,000)	(1,050,000)
Common unit repurchases									0
Other contributions									1,695,000
Net loss							(298,000)	(2,244,000)	(294,000)
Other comprehensive income (loss)							(358,000)	60,000	255,000
Partners' capital balance, ending	$ (7,705,000)		$ (6,692,000)		$ (3,932,000)		(7,705,000)	(6,692,000)	(3,932,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss							$ (298,000)	$ (2,244,000)	(294,000)
Other contributions									$ 1,695,000
Common Unitholders [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Partners' capital balance (in shares)		97,152,700		97,152,700		98,002,700	97,152,700	97,152,700	98,002,700
Partners' capital balance, beginning		$ (978,503,000)		$ (701,188,000)		$ (570,754,000)	$ (978,503,000)	$ (701,188,000)	$ (570,754,000)
Contributions in connection with non-cash ESOP and stock and unit-based compensation charges							5,579,000	13,582,000	18,018,000
Distributions							(9,716,000)	(38,862,000)	$ (78,936,000)
Common unit repurchases (in shares)									(850,000)
Common unit repurchases									$ (15,851,000)
Net loss							$ (63,605,000)	$ (252,035,000)	$ (53,665,000)
Partners' capital balance (in shares)	97,152,700		97,152,700		97,152,700		97,152,700	97,152,700	97,152,700
Partners' capital balance, ending	$ (1,046,245,000)		$ (978,503,000)		$ (701,188,000)		$ (1,046,245,000)	$ (978,503,000)	$ (701,188,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss							$ (63,605,000)	$ (252,035,000)	$ (53,665,000)
General Partner [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Partners' capital balance (in shares)		989,900		989,900		989,900	989,900	989,900	989,900
Partners' capital balance, beginning		$ (69,792,000)		$ (66,991,000)		$ (65,835,000)	$ (69,792,000)	$ (66,991,000)	$ (65,835,000)
Contributions in connection with non-cash ESOP and stock and unit-based compensation charges							56,000	137,000	183,000
Distributions							(98,000)	(392,000)	(797,000)
Net loss							$ (642,000)	$ (2,546,000)	$ (542,000)
Partners' capital balance (in shares)	989,900		989,900		989,900		989,900	989,900	989,900
Partners' capital balance, ending	$ (70,476,000)		$ (69,792,000)		$ (66,991,000)		$ (70,476,000)	$ (69,792,000)	$ (66,991,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss							(642,000)	(2,546,000)	(542,000)
Ferrellgas Partners Finance Corp. [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net loss							(3,999)	(2,115)	(5,308)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity balance		$ 2,850		$ 1,000		$ 1,000	2,850	1,000	1,000
Capital contribution							4,007	3,965	5,308
Net loss							(3,999)	(2,115)	(5,308)
Stockholders' equity balance	$ 2,858		$ 2,850		$ 1,000		$ 2,858	$ 2,850	$ 1,000
Ferrellgas Partners Finance Corp. [Member] | Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity balance (in shares)		1,000		1,000		1,000	1,000	1,000	1,000
Stockholders' equity balance		$ 1,000		$ 1,000		$ 1,000	$ 1,000	$ 1,000	$ 1,000
Stockholders' equity balance (in shares)	1,000		1,000		1,000		1,000	1,000	1,000
Stockholders' equity balance	$ 1,000		$ 1,000		$ 1,000		$ 1,000	$ 1,000	$ 1,000
Ferrellgas Partners Finance Corp. [Member] | Additional Paid-in Capital [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net loss							0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity balance		29,020		25,055		19,747	29,020	25,055	19,747
Capital contribution							4,007	3,965	5,308
Net loss							0	0	0
Stockholders' equity balance	33,027		29,020		25,055		33,027	29,020	25,055
Ferrellgas Partners Finance Corp. [Member] | Accumulated deficit [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net loss							(3,999)	(2,115)	(5,308)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity balance		(27,170)		(25,055)		(19,747)	(27,170)	(25,055)	(19,747)
Capital contribution							0	0	0
Net loss							(3,999)	(2,115)	(5,308)
Stockholders' equity balance	(31,169)		(27,170)		(25,055)		(31,169)	(27,170)	(25,055)
Ferrellgas, L.P. [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Partners' capital balance, beginning		(680,078,000)		(406,798,000)		(469,413,000)	(680,078,000)	(406,798,000)	(469,413,000)
Contributions in connection with non-cash ESOP and stock and unit-based compensation charges							5,693,000	13,859,000	18,386,000
Distributions							(41,121,000)	(70,962,000)	(119,879,000)
Other contributions									167,843,000
Net loss	(62,874,000)	(48,814,000)	(209,134,000)	(39,699,000)	(47,614,000)	(39,440,000)	(29,517,000)	(222,146,000)	(29,059,000)
Other comprehensive income (loss)							(35,380,000)	5,969,000	25,324,000
Partners' capital balance, ending	(780,403,000)		(680,078,000)		(406,798,000)		(780,403,000)	(680,078,000)	(406,798,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(62,874,000)	(48,814,000)	(209,134,000)	(39,699,000)	(47,614,000)	(39,440,000)	(29,517,000)	(222,146,000)	(29,059,000)
Other contributions									167,843,000
Ferrellgas, L.P. [Member] | Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Partners' Capital [Roll Forward]
Partners' capital balance, beginning		20,733,000		14,764,000		(10,560,000)	20,733,000	14,764,000	(10,560,000)
Other comprehensive income (loss)							(35,380,000)	5,969,000	25,324,000
Partners' capital balance, ending	(14,647,000)		20,733,000		14,764,000		(14,647,000)	20,733,000	14,764,000
Ferrellgas, L.P. [Member] | Common Unitholders [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Partners' capital balance, beginning		(693,896,000)		(417,467,000)		(454,222,000)	(693,896,000)	(417,467,000)	(454,222,000)
Contributions in connection with non-cash ESOP and stock and unit-based compensation charges							5,635,000	13,719,000	18,201,000
Distributions							(40,706,000)	(70,246,000)	(118,829,000)
Other contributions									166,148,000
Net loss							(29,219,000)	(219,902,000)	(28,765,000)
Partners' capital balance, ending	(758,186,000)		(693,896,000)		(417,467,000)		(758,186,000)	(693,896,000)	(417,467,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss							(29,219,000)	(219,902,000)	(28,765,000)
Other contributions									166,148,000
Ferrellgas, L.P. [Member] | General Partner [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Partners' capital balance, beginning		(6,915,000)		(4,095,000)		(4,631,000)	(6,915,000)	(4,095,000)	(4,631,000)
Contributions in connection with non-cash ESOP and stock and unit-based compensation charges							58,000	140,000	185,000
Distributions							(415,000)	(716,000)	(1,050,000)
Other contributions									1,695,000
Net loss							(298,000)	(2,244,000)	(294,000)
Partners' capital balance, ending	(7,570,000)		(6,915,000)		(4,095,000)		(7,570,000)	(6,915,000)	(4,095,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss							(298,000)	(2,244,000)	(294,000)
Other contributions									1,695,000
Ferrellgas Finance Corp. [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net loss							(5,625)	(5,216)	(5,516)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity balance		$ 2,600		$ 2,600		$ 2,600	2,600	2,600	2,600
Capital contribution							5,966	5,216	5,516
Net loss							(5,625)	(5,216)	(5,516)
Stockholders' equity balance	$ 2,941		$ 2,600		$ 2,600		$ 2,941	$ 2,600	$ 2,600
Ferrellgas Finance Corp. [Member] | Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity balance (in shares)		1,000		1,000		1,000	1,000	1,000	1,000
Stockholders' equity balance		$ 1,000		$ 1,000		$ 1,000	$ 1,000	$ 1,000	$ 1,000
Stockholders' equity balance (in shares)	1,000		1,000		1,000		1,000	1,000	1,000
Stockholders' equity balance	$ 1,000		$ 1,000		$ 1,000		$ 1,000	$ 1,000	$ 1,000
Ferrellgas Finance Corp. [Member] | Additional Paid-in Capital [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net loss							0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity balance		72,552		67,336		61,820	72,552	67,336	61,820
Capital contribution							5,966	5,216	5,516
Net loss							0	0	0
Stockholders' equity balance	78,518		72,552		67,336		78,518	72,552	67,336
Ferrellgas Finance Corp. [Member] | Accumulated deficit [Member]
Increase (Decrease) in Partners' Capital [Roll Forward]
Net loss							(5,625)	(5,216)	(5,516)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' equity balance		$ (70,952)		$ (65,736)		$ (60,220)	(70,952)	(65,736)	(60,220)
Capital contribution							0	0	0
Net loss							(5,625)	(5,216)	(5,516)
Stockholders' equity balance	$ (76,577)		$ (70,952)		$ (65,736)		$ (76,577)	$ (70,952)	$ (65,736)