Guarantor financial information - Condensed Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Oct. 31, 2016	Jul. 31, 2016	Oct. 31, 2015	Jul. 31, 2015
Current assets:
Cash and cash equivalents	$ 12,639	$ 4,965	$ 8,892	$ 7,652
Accounts and notes receivable	148,283	149,583
Inventories	100,296	90,594
Prepaid expenses and other current assets	31,820	39,973
Total current assets	293,038	285,115
Property, plant and equipment, net	757,940	774,680
Goodwill	256,103	256,103
Intangible assets, net	272,031	280,185
Other assets, net	88,103	87,223
Total assets	1,667,215	1,683,306
Current liabilities:
Accounts payable	74,788	67,928
Short-term borrowings	96,824	101,291
Collateralized note payable	74,000	64,000
Other current liabilities	170,527	128,958
Total current liabilities	416,139	362,177
Long-term debt	1,965,219	1,941,335
Other liabilities	32,755	31,574
Contingencies and commitments
Partners' capital
Partners' equity	(741,415)	(647,057)
Accumulated other comprehensive income (loss)	(1,186)	(10,468)
Total partners' capital	(746,898)	(651,780)
Total liabilities and partners' capital	1,667,215	1,683,306
Ferrellgas, L.P. [Member]
Current assets:
Cash and cash equivalents	12,565	4,890	8,608	5,600
Accounts and notes receivable	148,283	149,583
Intercompany receivables	0	0
Inventories	100,296	90,594
Prepaid expenses and other current assets	31,803	39,955
Total current assets	292,947	285,022
Property, plant and equipment, net	757,940	774,680
Goodwill	256,103	256,103
Intangible assets, net	272,031	280,185
Intercompany receivables	0	0
Investments in consolidated subsidiaries	0	0
Other assets, net	88,103	87,223
Total assets	1,667,124	1,683,213
Current liabilities:
Accounts payable	74,788	67,928
Short-term borrowings	96,824	101,291
Collateralized note payable	74,000	64,000
Intercompany Payables	0	0
Other current liabilities	164,597	126,952
Total current liabilities	410,209	360,171
Long-term debt	1,784,660	1,760,881
Other liabilities	32,755	31,574
Contingencies and commitments
Partners' capital
Partners' equity	(559,316)	(458,853)
Accumulated other comprehensive income (loss)	(1,184)	(10,560)
Total partners' capital	(560,500)	(469,413)
Total liabilities and partners' capital	1,667,124	1,683,213
Reportable Legal Entities [Member] | Ferrellgas, L.P. (Parent and Co-Issuer) [Member]
Current assets:
Cash and cash equivalents	12,368	4,472	6,029	5,579
Accounts and notes receivable	(9,133)	(2,703)
Intercompany receivables	21,421	34,089
Inventories	79,814	71,422
Prepaid expenses and other current assets	22,616	27,922
Total current assets	127,086	135,202
Property, plant and equipment, net	550,113	557,460
Goodwill	246,098	246,098
Intangible assets, net	137,625	141,794
Intercompany receivables	450,000	450,000
Investments in consolidated subsidiaries	1,890	3,630
Other assets, net	38,168	37,742
Total assets	1,550,980	1,571,926
Current liabilities:
Accounts payable	41,161	33,781
Short-term borrowings	96,824	101,291
Collateralized note payable	0	0
Intercompany Payables	0	0
Other current liabilities	161,172	119,048
Total current liabilities	299,157	254,120
Long-term debt	1,783,634	1,759,868
Other liabilities	28,689	27,351
Partners' capital
Partners' equity	(559,316)	(458,853)
Accumulated other comprehensive income (loss)	(1,184)	(10,560)
Total partners' capital	(560,500)	(469,413)
Total liabilities and partners' capital	1,550,980	1,571,926
Reportable Legal Entities [Member] | Ferrellgas Finance Corp. (Co-Issuer) [Member]
Current assets:
Cash and cash equivalents	1	1	1	1
Accounts and notes receivable	0	0
Intercompany receivables	0	0
Inventories	0	0
Prepaid expenses and other current assets	0	2
Total current assets	1	3
Property, plant and equipment, net	0	0
Goodwill	0	0
Intangible assets, net	0	0
Intercompany receivables	0	0
Investments in consolidated subsidiaries	0	0
Other assets, net	0	0
Total assets	1	3
Current liabilities:
Accounts payable	0	0
Short-term borrowings	0	0
Collateralized note payable	0	0
Intercompany Payables	0	0
Other current liabilities	0	0
Total current liabilities	0	0
Long-term debt	0	0
Other liabilities	0	0
Partners' capital
Partners' equity	1	3
Accumulated other comprehensive income (loss)	0	0
Total partners' capital	1	3
Total liabilities and partners' capital	1	3
Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	196	417	2,578	20
Accounts and notes receivable	56,051	45,822
Intercompany receivables	0	0
Inventories	20,482	19,172
Prepaid expenses and other current assets	9,185	12,029
Total current assets	85,914	77,440
Property, plant and equipment, net	207,827	217,220
Goodwill	10,005	10,005
Intangible assets, net	134,406	138,391
Intercompany receivables	0	0
Investments in consolidated subsidiaries	0	0
Other assets, net	49,282	49,016
Total assets	487,434	492,072
Current liabilities:
Accounts payable	33,627	34,147
Short-term borrowings	0	0
Collateralized note payable	0	0
Intercompany Payables	36,798	35,491
Other current liabilities	3,293	7,754
Total current liabilities	73,718	77,392
Long-term debt	451,026	451,013
Other liabilities	3,841	3,998
Partners' capital
Partners' equity	(40,504)	(39,684)
Accumulated other comprehensive income (loss)	(647)	(647)
Total partners' capital	(41,151)	(40,331)
Total liabilities and partners' capital	487,434	492,072
Reportable Legal Entities [Member] | Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	0	0	0	0
Accounts and notes receivable	101,365	106,464
Intercompany receivables	0	0
Inventories	0	0
Prepaid expenses and other current assets	2	2
Total current assets	101,367	106,466
Property, plant and equipment, net	0	0
Goodwill	0	0
Intangible assets, net	0	0
Intercompany receivables	0	0
Investments in consolidated subsidiaries	0	0
Other assets, net	653	465
Total assets	102,020	106,931
Current liabilities:
Accounts payable	0	0
Short-term borrowings	0	0
Collateralized note payable	74,000	64,000
Intercompany Payables	(15,377)	(1,402)
Other current liabilities	132	150
Total current liabilities	58,755	62,748
Long-term debt	0	0
Other liabilities	225	225
Partners' capital
Partners' equity	42,715	43,633
Accumulated other comprehensive income (loss)	325	325
Total partners' capital	43,040	43,958
Total liabilities and partners' capital	102,020	106,931
Eliminations [Member]
Current assets:
Cash and cash equivalents	0	0	$ 0	$ 0
Accounts and notes receivable	0	0
Intercompany receivables	(21,421)	(34,089)
Inventories	0	0
Prepaid expenses and other current assets	0	0
Total current assets	(21,421)	(34,089)
Property, plant and equipment, net	0	0
Goodwill	0	0
Intangible assets, net	0	0
Intercompany receivables	(450,000)	(450,000)
Investments in consolidated subsidiaries	(1,890)	(3,630)
Other assets, net	0	0
Total assets	(473,311)	(487,719)
Current liabilities:
Accounts payable	0	0
Short-term borrowings	0	0
Collateralized note payable	0	0
Intercompany Payables	(21,421)	(34,089)
Other current liabilities	0	0
Total current liabilities	(21,421)	(34,089)
Long-term debt	(450,000)	(450,000)
Other liabilities	0	0
Partners' capital
Partners' equity	(2,212)	(3,952)
Accumulated other comprehensive income (loss)	322	322
Total partners' capital	(1,890)	(3,630)
Total liabilities and partners' capital	$ (473,311)	$ (487,719)