Segment Reporting Segment Reporting (Schedule of Capital Expenditure Information, by Segment) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jan. 31, 2018	Jan. 31, 2017
Segment Reporting Information
Capital Expenditures	$ 32,767	$ 17,096
Propane and related equipment sales [Member]
Segment Reporting Information
Capital Expenditures	30,327	15,408
Corporate Segment [Member]
Segment Reporting Information
Capital Expenditures	1,245	1,484
Midstream Operations [Member]
Segment Reporting Information
Capital Expenditures	1,195	204
Maintenance Capital Expenditures [Member]
Segment Reporting Information
Capital Expenditures	13,443	7,239
Maintenance Capital Expenditures [Member] | Propane and related equipment sales [Member]
Segment Reporting Information
Capital Expenditures	12,016	5,551
Maintenance Capital Expenditures [Member] | Corporate Segment [Member]
Segment Reporting Information
Capital Expenditures	1,245	1,484
Maintenance Capital Expenditures [Member] | Midstream Operations [Member]
Segment Reporting Information
Capital Expenditures	182	204
Growth Capital Expenditures [Member]
Segment Reporting Information
Capital Expenditures	19,324	9,857
Growth Capital Expenditures [Member] | Propane and related equipment sales [Member]
Segment Reporting Information
Capital Expenditures	18,311	9,857
Growth Capital Expenditures [Member] | Corporate Segment [Member]
Segment Reporting Information
Capital Expenditures	0	0
Growth Capital Expenditures [Member] | Midstream Operations [Member]
Segment Reporting Information
Capital Expenditures	1,013	0
Ferrellgas, L.P. [Member]
Segment Reporting Information
Capital Expenditures	32,767	17,096
Ferrellgas, L.P. [Member] | Propane and related equipment sales [Member]
Segment Reporting Information
Capital Expenditures	30,327	15,408
Ferrellgas, L.P. [Member] | Corporate Segment [Member]
Segment Reporting Information
Capital Expenditures	1,245	1,484
Ferrellgas, L.P. [Member] | Midstream Operations [Member]
Segment Reporting Information
Capital Expenditures	1,195	204
Ferrellgas, L.P. [Member] | Maintenance Capital Expenditures [Member]
Segment Reporting Information
Capital Expenditures	13,443	7,239
Ferrellgas, L.P. [Member] | Maintenance Capital Expenditures [Member] | Propane and related equipment sales [Member]
Segment Reporting Information
Capital Expenditures	12,016	5,551
Ferrellgas, L.P. [Member] | Maintenance Capital Expenditures [Member] | Corporate Segment [Member]
Segment Reporting Information
Capital Expenditures	1,245	1,484
Ferrellgas, L.P. [Member] | Maintenance Capital Expenditures [Member] | Midstream Operations [Member]
Segment Reporting Information
Capital Expenditures	182	204
Ferrellgas, L.P. [Member] | Growth Capital Expenditures [Member]
Segment Reporting Information
Capital Expenditures	19,324	9,857
Ferrellgas, L.P. [Member] | Growth Capital Expenditures [Member] | Propane and related equipment sales [Member]
Segment Reporting Information
Capital Expenditures	18,311	9,857
Ferrellgas, L.P. [Member] | Growth Capital Expenditures [Member] | Corporate Segment [Member]
Segment Reporting Information
Capital Expenditures	0	0
Ferrellgas, L.P. [Member] | Growth Capital Expenditures [Member] | Midstream Operations [Member]
Segment Reporting Information
Capital Expenditures	$ 1,013	$ 0