Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011		Sep. 30, 2011
Segment information
Revenues	$ 1,277.2		$ 1,105.4		$ 5,393.5		$ 5,052.0
Cost of sales	810.2		731.0		3,438.6		3,317.5
Segment profit:
Operating income (loss)	(19.2)		17.2		549.9		626.5
Loss from equity investees	(0.1)		(0.2)		(0.2)		(0.8)
Gain (loss) on extinguishment of debt	0.1		0		(13.3)		(18.8)
Interest expense	(61.3)		(35.0)		(162.6)		(102.6)
Income (loss) before income taxes	(80.5)		(18.0)		373.8		504.3
Noncontrolling interests' net income (loss)	(70.2)		(6.3)		46.5		101.8
Depreciation and amortization	84.6		57.8		227.7		168.6
Capital expenditures	83.7		78.5		237.7		246.1
Total assets (at period end)	9,652.2		6,673.7		9,652.2		6,673.7		6,663.3
Bank loans (at period end)	187.3		206.1		187.3		206.1		138.7
Goodwill (at period end)	2,756.0		1,612.0		2,756.0		1,612.0		1,562.2
Eliminations [Member]
Segment information
Revenues	(32.2)	[1]	(40.0)	[1]	(129.1)	[1]	(172.9)	[1]
Cost of sales	(30.9)	[1]	(39.1)	[1]	(125.6)	[1]	(170.3)	[1]
Segment profit:
Operating income (loss)			0				0.2
Income (loss) before income taxes			0				0.2
Total assets (at period end)	(87.4)		(81.0)		(87.4)		(81.0)
AmeriGas Propane [Member]
Segment information
Revenues	571.9		470.8		2,411.3		2,077.8
Cost of sales	334.0		300.8		1,447.8		1,300.9
Segment profit:
Operating income (loss)	(48.4)		6.7		206.7		252.9
Loss from equity investees	0
Gain (loss) on extinguishment of debt	0.1		0		(13.3)		(18.8)
Interest expense	(41.8)		(15.7)		(103.4)		(47.4)
Income (loss) before income taxes	(90.1)		(9.0)		90.0		186.7
Partnership EBITDA	1.8	[2],[3]	31.1	[2],[3]	310.0	[4],[5]	301.9	[4],[5]
Noncontrolling interests' net income (loss)	(70.0)		(6.1)		46.2		101.2
Depreciation and amortization	49.5		24.5		118.5		70.4
Capital expenditures	25.2		18.6		70.3		59.2
Total assets (at period end)	4,579.5		1,772.1		4,579.5		1,772.1
Bank loans (at period end)	68.8		176.0		68.8		176.0
Goodwill (at period end)	1,866.7		695.8		1,866.7		695.8
Gas Utility [Member]
Segment information
Revenues	122.3		148.1		696.8		921.7
Cost of sales	51.4		78.8		370.6		562.3
Segment profit:
Operating income (loss)	22.5		17.2		168.7		193.2
Loss from equity investees	0
Interest expense	(9.9)		(9.9)		(30.1)		(30.2)
Income (loss) before income taxes	12.6		7.3		138.6		163.0
Depreciation and amortization	12.3		11.6		36.6		36.1
Capital expenditures	29.0		20.9		76.5		54.5
Total assets (at period end)	2,027.0		2,002.0		2,027.0		2,002.0
Goodwill (at period end)	182.1		180.1		182.1		180.1
Electric Utility [Member]
Segment information
Revenues	20.8		24.1		71.9		84.7
Cost of sales	11.3		14.6		41.8		53.4
Segment profit:
Operating income (loss)	2.6		2.4		9.2		9.0
Loss from equity investees	0
Interest expense	(0.6)		(0.7)		(1.7)		(1.8)
Income (loss) before income taxes	2.0		1.7		7.5		7.2
Depreciation and amortization	0.9		1.1		2.8		3.1
Capital expenditures	0.9		1.0		3.2		5.1
Total assets (at period end)	158.8		156.5		158.8		156.5
Midstream & Marketing [Member]
Segment information
Revenues	166.7		217.1		674.5		857.0
Cost of sales	145.2		193.1		565.6		738.6
Segment profit:
Operating income (loss)	4.9		8.4		59.4		76.7
Loss from equity investees	0
Interest expense	(1.2)		(0.6)		(3.6)		(2.0)
Income (loss) before income taxes	3.7		7.8		55.8		74.7
Depreciation and amortization	3.2		1.8		9.0		5.4
Capital expenditures	13.6		18.7		47.6		81.5
Total assets (at period end)	616.3		572.2		616.3		572.2
Bank loans (at period end)	95.0				95.0
Goodwill (at period end)	2.8		2.8		2.8		2.8
International Propane, Antargaz [Member]
Segment information
Revenues	211.8		161.0		958.7		889.7
Cost of sales	133.6		95.3		597.9		554.0
Segment profit:
Operating income (loss)	(1.2)		(11.4)		96.3		101.0
Loss from equity investees	(0.1)		(0.2)		(0.2)		(0.8)
Interest expense	(6.3)		(7.1)		(19.7)		(18.5)
Income (loss) before income taxes	(7.6)		(18.7)		76.4		81.7
Noncontrolling interests' net income (loss)	(0.2)		(0.2)		0.3		0.6
Depreciation and amortization	13.5		13.5		42.6		38.4
Capital expenditures	12.0		12.0		28.0		31.8
Total assets (at period end)	1,664.7		1,678.2		1,664.7		1,678.2
Goodwill (at period end)	605.0		641.1		605.0		641.1
International Propane, Flaga & Other [Member]
Segment information
Revenues	193.4	[6]	102.3	[6]	646.5	[6]	332.4	[6]
Cost of sales	153.0	[6]	74.6	[6]	506.3	[6]	243.8	[6]
Segment profit:
Operating income (loss)	2.4	[6]	(3.6)	[6]	16.8	[6]	(0.2)	[6]
Loss from equity investees	0
Interest expense	(1.2)	[6]	(0.8)	[6]	(3.4)	[6]	(2.1)	[6]
Income (loss) before income taxes	1.2	[6]	(4.4)	[6]	13.4	[6]	(2.3)	[6]
Depreciation and amortization	4.7	[6]	4.7	[6]	16.6	[6]	13.7	[6]
Capital expenditures	2.8	[6]	6.6	[6]	11.5	[6]	12.6	[6]
Total assets (at period end)	513.2	[6]	407.3	[6]	513.2	[6]	407.3	[6]
Bank loans (at period end)	23.5	[6]	30.1	[6]	23.5	[6]	30.1	[6]
Goodwill (at period end)	92.4	[6]	85.3	[6]	92.4	[6]	85.3	[6]
Corporate & Other [Member]
Segment information
Revenues	22.5	[6]	22.0	[6]	62.9	[7]	61.6	[7]
Cost of sales	12.6	[6]	12.9	[6]	34.2	[7]	34.8	[7]
Segment profit:
Operating income (loss)	(2.0)	[6]	(2.5)	[6]	(7.2)	[7]	(6.3)	[7]
Loss from equity investees	0
Interest expense	(0.3)	[6]	(0.2)	[6]	(0.7)	[7]	(0.6)	[7]
Income (loss) before income taxes	(2.3)	[6]	(2.7)	[6]	(7.9)	[7]	(6.9)	[7]
Depreciation and amortization	0.5	[6]	0.6	[6]	1.6	[7]	1.5	[7]
Capital expenditures	0.2	[6]	0.7	[6]	0.6	[7]	1.4	[7]
Total assets (at period end)	180.1	[6],[7]	166.4	[6],[7]	180.1	[6],[7]	166.4	[6],[7]
Goodwill (at period end)	$ 7.0	[6],[7]	$ 6.9	[6],[7]	$ 7.0	[6],[7]	$ 6.9	[6],[7]

[1] Principally represents the elimination of intersegment transactions among Midstream & Marketing, Gas Utility and AmeriGas Propane.

[2] Includes $0.1 gain associated with extinguishments of Partnership debt in 2012.

[3] The following table provides a reconciliation of Partnership EBITDA to AmeriGas Propane operating income (loss):Three Months Ended June 30, 2012 2011Partnership EBITDA (ii) $1.8 $31.1Depreciation and amortization (49.5) (24.5)Gain on extinguishments of debt (0.1) —Noncontrolling interests (i) (0.6) 0.1Operating (loss) income $(48.4) $6.7

[4] Includes $13.3 loss and $18.8 loss, respectively, associated with extinguishments of Partnership debt.

[5] The following table provides a reconciliation of Partnership EBITDA to AmeriGas Propane operating income:Nine Months Ended June 30, 2012 2011Partnership EBITDA (ii) $310.0 $301.9Depreciation and amortization (118.5) (70.4)Loss on extinguishment of debt 13.3 18.8Noncontrolling interests (i) 1.9 2.6Operating income $206.7 $252.9

[6] International Propane—Flaga & Other principally comprises Flaga’s retail distribution businesses, our propane distribution business in China and our propane distribution business in the United Kingdom.

[7] Corporate & Other results principally comprise HVAC/R, net expenses of UGI’s captive general liability insurance company and UGI Corporation’s unallocated corporate and general expenses and interest income. Corporate & Other assets principally comprise cash, short-term investments, assets of HVAC/R and an intercompany loan. The intercompany loan and associated interest is removed in the segment presentation.