Segment Reporting Segment Reporting (Schedule of Capital Expenditure Information, by Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015
Statement [Line Items]
Capital Expenditures	$ 46,365	$ 112,935	$ 69,837
Propane and related equipment sales [Member]
Statement [Line Items]
Capital Expenditures	42,242	46,393	52,978
Midstream - Crude Oil Logistics [Member]
Statement [Line Items]
Capital Expenditures	1,049	63,773	14,502
Corporate and Other [Member]
Statement [Line Items]
Capital Expenditures	3,074	2,769	2,357
Maintenance Capital Expenditures [Member]
Statement [Line Items]
Capital Expenditures	17,138	16,877	19,449
Maintenance Capital Expenditures [Member] | Propane and related equipment sales [Member]
Statement [Line Items]
Capital Expenditures	13,330	13,487	16,020
Maintenance Capital Expenditures [Member] | Midstream - Crude Oil Logistics [Member]
Statement [Line Items]
Capital Expenditures	734	621	1,072
Maintenance Capital Expenditures [Member] | Corporate and Other [Member]
Statement [Line Items]
Capital Expenditures	3,074	2,769	2,357
Growth Capital Expenditures [Member]
Statement [Line Items]
Capital Expenditures	29,227	96,058	50,388
Growth Capital Expenditures [Member] | Propane and related equipment sales [Member]
Statement [Line Items]
Capital Expenditures	28,912	32,906	36,958
Growth Capital Expenditures [Member] | Midstream - Crude Oil Logistics [Member]
Statement [Line Items]
Capital Expenditures	315	63,152	13,430
Growth Capital Expenditures [Member] | Corporate and Other [Member]
Statement [Line Items]
Capital Expenditures	0	0	0
Ferrellgas, L.P. [Member]
Statement [Line Items]
Capital Expenditures	46,365	112,935	69,837
Ferrellgas, L.P. [Member] | Propane and related equipment sales [Member]
Statement [Line Items]
Capital Expenditures	42,242	46,393	52,978
Ferrellgas, L.P. [Member] | Midstream - Crude Oil Logistics [Member]
Statement [Line Items]
Capital Expenditures	1,049	63,773	14,502
Ferrellgas, L.P. [Member] | Corporate and Other [Member]
Statement [Line Items]
Capital Expenditures	3,074	2,769	2,357
Ferrellgas, L.P. [Member] | Maintenance Capital Expenditures [Member]
Statement [Line Items]
Capital Expenditures	17,138	16,877	19,449
Ferrellgas, L.P. [Member] | Maintenance Capital Expenditures [Member] | Propane and related equipment sales [Member]
Statement [Line Items]
Capital Expenditures	13,330	13,487	16,020
Ferrellgas, L.P. [Member] | Maintenance Capital Expenditures [Member] | Midstream - Crude Oil Logistics [Member]
Statement [Line Items]
Capital Expenditures	734	621	1,072
Ferrellgas, L.P. [Member] | Maintenance Capital Expenditures [Member] | Corporate and Other [Member]
Statement [Line Items]
Capital Expenditures	3,074	2,769	2,357
Ferrellgas, L.P. [Member] | Growth Capital Expenditures [Member]
Statement [Line Items]
Capital Expenditures	29,227	96,058	50,388
Ferrellgas, L.P. [Member] | Growth Capital Expenditures [Member] | Propane and related equipment sales [Member]
Statement [Line Items]
Capital Expenditures	28,912	32,906	36,958
Ferrellgas, L.P. [Member] | Growth Capital Expenditures [Member] | Midstream - Crude Oil Logistics [Member]
Statement [Line Items]
Capital Expenditures	315	63,152	13,430
Ferrellgas, L.P. [Member] | Growth Capital Expenditures [Member] | Corporate and Other [Member]
Statement [Line Items]
Capital Expenditures	$ 0	$ 0	$ 0