Guarantor financial information Condensed Consolidated 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
Revenues:
Propane and other gas liquids sales													$ 1,318,412	$ 1,202,368	$ 1,657,016
Midstream operations													466,703	625,238	107,189
Other													145,162	211,761	260,185
Total revenues	$ 433,376	$ 538,109	$ 579,250	$ 379,542	$ 409,511	$ 509,472	$ 649,238	$ 471,146	$ 382,511	$ 532,551	$ 665,973	$ 443,355	1,930,277	2,039,367	2,024,390
Costs and expenses:
Cost of product sold - propane and other gas liquids sales													694,155	564,433	977,224
Cost of sales - midstream operations													429,439	471,234	76,590
Cost of product sold - other													67,267	126,237	170,697
Operating expense													432,412	459,178	437,457
Depreciation and amortization expense													103,351	150,513	98,579
General and administrative expense													49,617	56,635	77,238
Equipment lease expense													29,124	28,833	24,273
Employee Stock Ownership Plan (ESOP), Compensation Expense													15,088	27,595	24,713
Asset Impairment Charges					628,800								0	658,118	0
Loss on disposal of assets													14,457	30,835	7,099
Operating Income (Loss)													95,367	(534,244)	130,520
Interest and Debt Expense													(152,485)	(137,937)	(100,396)
Other income (expense), net													1,474	110	(350)
Earnings (loss) before income taxes													(55,644)	(672,071)	29,774
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
Other comprehensive income (loss)													25,324	28,758	(45,576)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest													(29,177)	(643,277)	(15,487)
Parent Company [Member]
Costs and expenses:
General and administrative expense													139	520	104
Operating Income (Loss)													(28,904)	(649,291)	45,854
Interest and Debt Expense													(25,297)	(16,119)	(16,169)
Income tax expense													(6)	(5)	69
Equity in earnings (loss) of Ferrellgas, L.P.													(28,765)	(648,771)	45,958
Net earnings (loss)													(54,207)	(665,415)	29,620
Ferrellgas, L.P. [Member]
Revenues:
Propane and other gas liquids sales													1,318,412	1,202,368	1,657,016
Midstream operations													466,703	625,238	107,189
Other													145,162	211,761	260,185
Total revenues	433,376	538,109	579,250	379,542	409,511	509,472	649,238	471,146	382,511	532,551	665,973	443,355	1,930,277	2,039,367	2,024,390
Costs and expenses:
Cost of product sold - propane and other gas liquids sales													694,155	564,433	977,224
Cost of sales - midstream operations													429,439	471,234	76,590
Cost of product sold - other													67,267	126,237	170,697
Operating expense													432,412	459,178	437,353
Depreciation and amortization expense													103,351	150,513	98,579
General and administrative expense													49,478	56,115	77,238
Equipment lease expense													29,124	28,833	24,273
Employee Stock Ownership Plan (ESOP), Compensation Expense													15,088	27,595	24,713
Asset Impairment Charges					628,800								0	658,118	0
Loss on disposal of assets													14,457	30,835	7,099
Operating Income (Loss)													95,506	(533,724)	130,624
Interest and Debt Expense													(127,188)	(121,818)	(84,227)
Loss on extinguishment of debt													0	0	0
Other income (expense), net													1,474	110	(354)
Earnings (loss) before income taxes													(30,208)	(655,432)	46,043
Income tax expense													(1,149)	(41)	(384)
Equity in earnings (loss) of Ferrellgas, L.P.													0	0	0
Net earnings (loss)	$ (47,614)	$ 15,395	$ 42,600	$ (39,440)	$ (664,091)	$ 23,049	$ 62,187	$ (76,536)	$ (55,249)	$ 40,404	$ 90,409	$ (29,137)	(29,059)	(655,391)	46,427
Other comprehensive income (loss)													25,324	28,758	(45,576)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest													(3,735)	(626,633)	851
Reportable Legal Entities [Member] | Parent Company [Member]
Revenues:
Propane and other gas liquids sales													1,318,412	1,202,368	1,657,016
Midstream operations													0	0	0
Other													69,962	73,200	73,704
Total revenues													1,388,374	1,275,568	1,730,720
Costs and expenses:
Cost of product sold - propane and other gas liquids sales													694,155	564,433	977,224
Cost of sales - midstream operations													0	(1,545)	0
Cost of product sold - other													8,473	8,867	7,649
Operating expense													398,584	399,680	413,112
Depreciation and amortization expense													72,919	75,059	75,834
General and administrative expense													44,810	50,592	76,250
Equipment lease expense													28,560	28,322	24,213
Employee Stock Ownership Plan (ESOP), Compensation Expense													15,088	27,595	24,713
Asset Impairment Charges														0
Loss on disposal of assets													9,198	9,180	7,095
Operating Income (Loss)													116,587	113,385	124,630
Interest and Debt Expense													(80,866)	(77,493)	(72,765)
Other income (expense), net													850	110	(354)
Earnings (loss) before income taxes													36,571	36,002	51,511
Income tax expense													217	839	292
Equity in earnings (loss) of Ferrellgas, L.P.													(65,413)	(690,554)	(4,792)
Net earnings (loss)													(29,059)	(655,391)	46,427
Other comprehensive income (loss)													25,324	28,758	(45,576)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest													(3,735)	(626,633)	851
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Revenues:
Propane and other gas liquids sales													0	0	0
Midstream operations													466,703	625,238	107,189
Other													75,200	138,561	186,481
Total revenues													541,903	763,799	293,670
Costs and expenses:
Cost of product sold - propane and other gas liquids sales													0	0	0
Cost of sales - midstream operations													429,439	472,779	76,590
Cost of product sold - other													58,794	117,370	163,048
Operating expense													38,188	58,789	25,189
Depreciation and amortization expense													30,183	75,212	22,745
General and administrative expense													4,663	5,516	984
Equipment lease expense													564	511	60
Employee Stock Ownership Plan (ESOP), Compensation Expense													0	0	0
Asset Impairment Charges														658,118
Loss on disposal of assets													5,259	21,655	4
Operating Income (Loss)													(25,187)	(646,151)	5,050
Interest and Debt Expense													(43,839)	(42,325)	(8,499)
Other income (expense), net													624	0	0
Earnings (loss) before income taxes													(68,402)	(688,476)	(3,449)
Income tax expense													(1,366)	(880)	(676)
Equity in earnings (loss) of Ferrellgas, L.P.													0	0	0
Net earnings (loss)													(67,036)	(687,596)	(2,773)
Other comprehensive income (loss)													0	0	2
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest													(67,036)	(687,596)	(2,771)
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Revenues:
Propane and other gas liquids sales													0	0	0
Midstream operations													0	0	0
Other													0	0	0
Total revenues													0	0	0
Costs and expenses:
Cost of product sold - propane and other gas liquids sales													0	0	0
Cost of sales - midstream operations													0	0	0
Cost of product sold - other													0	0	0
Operating expense													95	4,028	5,206
Depreciation and amortization expense													249	242	0
General and administrative expense													0	0	0
Equipment lease expense													0	0	0
Employee Stock Ownership Plan (ESOP), Compensation Expense													0	0	0
Asset Impairment Charges														0
Loss on disposal of assets													0	0	0
Operating Income (Loss)													(344)	(4,270)	(5,206)
Interest and Debt Expense													(2,480)	(2,186)	(2,622)
Other income (expense), net													4,452	3,505	5,813
Earnings (loss) before income taxes													1,628	(2,951)	(2,015)
Income tax expense													0	0	0
Equity in earnings (loss) of Ferrellgas, L.P.													0	0	0
Net earnings (loss)													1,628	(2,951)	(2,015)
Other comprehensive income (loss)													0	0	(4)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest													1,628	(2,951)	(2,019)
Reportable Legal Entities [Member] | Co-issuer [Member]
Revenues:
Propane and other gas liquids sales													0	0	0
Midstream operations													0	0	0
Other													0	0	0
Total revenues													0	0	0
Costs and expenses:
Cost of product sold - propane and other gas liquids sales													0	0	0
Cost of sales - midstream operations													0	0	0
Cost of product sold - other													0	0	0
Operating expense													0	0	0
Depreciation and amortization expense													0	0	0
General and administrative expense													5	7	4
Equipment lease expense													0	0	0
Employee Stock Ownership Plan (ESOP), Compensation Expense													0	0	0
Asset Impairment Charges														0
Loss on disposal of assets													0	0	0
Operating Income (Loss)													(5)	(7)	(4)
Interest and Debt Expense													0	0	0
Other income (expense), net													0	0	0
Earnings (loss) before income taxes													(5)	(7)	(4)
Income tax expense													0	0	0
Equity in earnings (loss) of Ferrellgas, L.P.													0	0	0
Net earnings (loss)													(5)	(7)	(4)
Other comprehensive income (loss)													0	0	0
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest													(5)	(7)	(4)
Eliminations [Member]
Revenues:
Propane and other gas liquids sales													0	0	0
Midstream operations													0	0	0
Other													0	0	0
Total revenues													0	0	0
Costs and expenses:
Cost of product sold - propane and other gas liquids sales													0	0	0
Cost of sales - midstream operations													0	0	0
Cost of product sold - other													0	0	0
Operating expense													(4,455)	(3,319)	(6,154)
Depreciation and amortization expense													0	0	0
General and administrative expense													0	0	0
Equipment lease expense													0	0	0
Employee Stock Ownership Plan (ESOP), Compensation Expense													0	0	0
Asset Impairment Charges														0
Loss on disposal of assets													0	0	0
Operating Income (Loss)													4,455	3,319	6,154
Interest and Debt Expense													(3)	186	(341)
Other income (expense), net													(4,452)	(3,505)	(5,813)
Earnings (loss) before income taxes													0	0	0
Income tax expense													0	0	0
Equity in earnings (loss) of Ferrellgas, L.P.													65,413	690,554	4,792
Net earnings (loss)													65,413	690,554	4,792
Other comprehensive income (loss)													0	0	2
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest													$ 65,413	$ 690,554	$ 4,794