Debt (Details) (USD $)	3 Months Ended	12 Months Ended
	Oct. 31, 2011 years	Jul. 31, 2011
Debt Instrument [Line Items]
Short-term borrowings	$ 126,071,000	$ 64,927,000
Ferrellgas, L.P. And Subsidiaries [Member]
Debt Instrument [Line Items]
Short-term borrowings	126,071,000	64,927,000
Letter Of Credit [Member]
Debt Instrument [Line Items]
Letters of credit outstanding	51,000,000	47,500,000
Letter of credit facility, remaining capacity	139,600,000	152,500,000
Letter Of Credit [Member] | Ferrellgas, L.P. And Subsidiaries [Member]
Debt Instrument [Line Items]
Letters of credit outstanding	51,000,000	47,500,000
Letter of credit facility, remaining capacity	139,600,000	152,500,000
Secured Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maturity period	5
Secured line of credit facility	400,000,000
Debt instrument, maturity date	September 2016
Line of credit facility	209,300,000	129,500,000
Amount classified as long-term debt	83,200,000	64,600,000
Weighted average interest rate of secured credit facility	3.27%	4.57%
Secured Credit Facility [Member] | Ferrellgas, L.P. And Subsidiaries [Member]
Debt Instrument [Line Items]
Line of credit facility, maturity period	5
Secured line of credit facility	400,000,000
Debt instrument, maturity date	September 2016
Line of credit facility	209,300,000	129,500,000
Amount classified as long-term debt	83,200,000	64,600,000
Weighted average interest rate of secured credit facility	3.27%	4.57%
Secured Credit Facility [Member] | Letter Of Credit [Member]
Debt Instrument [Line Items]
Secured line of credit facility	200,000,000
Secured Credit Facility [Member] | Letter Of Credit [Member] | Ferrellgas, L.P. And Subsidiaries [Member]
Debt Instrument [Line Items]
Secured line of credit facility	$ 200,000,000
Reductions From Previous Facility Rate [Member] | Secured Credit Facility [Member]
Debt Instrument [Line Items]
Interest rate, minimum	1.25%
Interest rate, maximum	1.50%
Reductions From Previous Facility Rate [Member] | Secured Credit Facility [Member] | Ferrellgas, L.P. And Subsidiaries [Member]
Debt Instrument [Line Items]
Interest rate, minimum	1.25%
Interest rate, maximum	1.50%