Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012		Sep. 30, 2012
Segment information
Revenues	$ 1,372.3		$ 1,277.2		$ 5,932.6		$ 5,393.5
Cost of sales	827.9		810.2		3,547.3		3,438.6
Segment profit:
Operating income (loss)	53.1		(19.2)		835.4		549.9
(Loss) income from equity investees	0		(0.1)		0.1		(0.2)
Gain (loss) on extinguishment of debt	0		0.1		0		(13.3)
Interest expense	(59.2)		(61.3)		(179.6)		(162.6)
Income (loss) before income taxes	(6.1)		(80.5)		655.9		373.8
Noncontrolling interests' net income (loss)	(29.8)		(70.2)		192.6		46.5
Depreciation and amortization	91.9		84.6		266.3		227.7
Capital expenditures	107.6		83.7		292.5		237.7
Total assets (at period end)	9,828.8		9,652.2		9,828.8		9,652.2		9,709.7
Bank loans (at period end)	135.9		187.3		135.9		187.3		165.1
Goodwill (at period end)	2,834.0		2,756.0		2,834.0		2,756.0		2,818.3
Eliminations [Member]
Segment information
Revenues	(61.5)	[1]	(33.4)	[1]	(181.1)	[1]	(134.2)	[1]
Cost of sales	(60.1)	[1]	(32.1)	[1]	(176.2)	[1]	(130.7)	[1]
Segment profit:
Operating income (loss)	(0.2)	[1]			(1.1)	[1]	0
Income (loss) before income taxes	(0.2)		0		(1.1)		0
Depreciation and amortization	(0.1)				(0.1)
Capital expenditures	(0.1)				(1.1)
Total assets (at period end)	(95.9)		(87.4)		(95.9)		(87.4)
AmeriGas Propane [Member]
Segment information
Revenues	581.7		571.9		2,634.6		2,411.3
Cost of sales	305.7		334.0		1,370.2		1,447.8
Segment profit:
Operating income (loss)	6.6		(48.4)		403.9		206.7
Gain (loss) on extinguishment of debt	0		0.1		0		(13.3)
Interest expense	(41.2)		(41.8)		(124.2)		(103.4)
Income (loss) before income taxes	(34.6)		(90.1)		279.7		90.0
Partnership EBITDA	59.1	[2]	1.8	[2]	550.5	[3]	310.0	[3]
Noncontrolling interests' net income (loss)	(29.6)		(70.0)		192.4		46.2
Depreciation and amortization	52.5		49.5		150.5		118.5
Capital expenditures	26.3		25.2		80.7		70.3
Total assets (at period end)	4,388.1		4,579.5		4,388.1		4,579.5
Bank loans (at period end)	80.0		68.8		80.0		68.8
Goodwill (at period end)	1,929.2		1,866.7		1,929.2		1,866.7
Noncontrolling Interests Principally General Partners Interest in Related Parties	0	[4]	(0.6)	[4]	3.9	[4]	1.9	[4]
Gas Utility [Member]
Segment information
Revenues	126.7		122.3		743.6		696.8
Cost of sales	52.4		51.4		372.7		370.6
Segment profit:
Operating income (loss)	16.1		22.5		191.6		168.7
Interest expense	(9.2)		(9.9)		(28.1)		(30.1)
Income (loss) before income taxes	6.9		12.6		163.5		138.6
Depreciation and amortization	13.1		12.3		38.4		36.6
Capital expenditures	37.3		29.0		90.2		76.5
Total assets (at period end)	2,164.4		2,027.0		2,164.4		2,027.0
Bank loans (at period end)	0		0		0		0
Goodwill (at period end)	182.1		182.1		182.1		182.1
Midstream And Marketing, Energy Services [Member]
Segment information
Revenues	233.0		157.0		764.8		652.5
Cost of sales	213.9		140.0		648.8		553.1
Segment profit:
Operating income (loss)	7.4		6.8		78.2		67.3
Interest expense	(0.6)		(1.2)		(2.4)		(3.6)
Income (loss) before income taxes	6.8		5.6		75.8		63.7
Depreciation and amortization	2.1		0.9		5.6		2.4
Capital expenditures	22.0		7.3		54.8		30.2
Total assets (at period end)	437.0		355.0		437.0		355.0
Bank loans (at period end)	45.5		95.0		45.5		95.0
Goodwill (at period end)	2.8		2.8		2.8		2.8
Midstream & Marketing, Electric Generation [Member]
Segment information
Revenues	15.7		10.9		47.7		27.1
Cost of sales	7.7		6.4		27.9		17.6
Segment profit:
Operating income (loss)	0.8		(1.9)		1.5		(7.9)
Interest expense	0		0		0		0
Income (loss) before income taxes	0.8		(1.9)		1.5		(7.9)
Depreciation and amortization	2.6		2.3		7.5		6.6
Capital expenditures	4.4		6.3		15.4		17.4
Total assets (at period end)	267.2		261.3		267.2		261.3
Bank loans (at period end)	0		0		0		0
Goodwill (at period end)	0		0		0		0
International Propane, Antargaz [Member]
Segment information
Revenues	249.2		211.8		1,121.1		958.7
Cost of sales	148.7		133.6		714.4		597.9
Segment profit:
Operating income (loss)	14.5		(1.2)		129.8		96.3
(Loss) income from equity investees	0		(0.1)		0.1		(0.2)
Interest expense	(6.2)		(6.3)		(19.0)		(19.7)
Income (loss) before income taxes	8.3		(7.6)		110.9		76.4
Noncontrolling interests' net income (loss)	(0.3)		(0.2)		0.1		0.3
Depreciation and amortization	14.0		13.5		42.3		42.6
Capital expenditures	11.7		12.0		37.1		28.0
Total assets (at period end)	1,771.7		1,664.7		1,771.7		1,664.7
Goodwill (at period end)	619.2		605.0		619.2		605.0
International Propane, Flaga & Other [Member]
Segment information
Revenues	182.5		193.4		659.0		646.5
Cost of sales	134.8		153.0		507.1		506.3
Segment profit:
Operating income (loss)	6.5		2.4		30.6		16.8
Interest expense	(1.2)		(1.2)		(3.8)		(3.4)
Income (loss) before income taxes	5.3		1.2		26.8		13.4
Noncontrolling interests' net income (loss)	0.1				0.1
Depreciation and amortization	6.1		4.7		17.4		16.6
Capital expenditures	4.0		2.8		10.3		11.5
Total assets (at period end)	543.1		513.2		543.1		513.2
Bank loans (at period end)	10.4		23.5		10.4		23.5
Goodwill (at period end)	93.7		92.4		93.7		92.4
Corporate & Other [Member]
Segment information
Revenues	45.0	[5]	43.3	[5]	142.9	[5]	134.8	[5]
Cost of sales	24.8	[5]	23.9	[5]	82.4	[5]	76.0	[5]
Segment profit:
Operating income (loss)	1.4	[5]	0.6	[5]	0.9	[5]	2.0	[5]
Interest expense	(0.8)	[5]	(0.9)	[5]	(2.1)	[5]	(2.4)	[5]
Income (loss) before income taxes	0.6	[5]	(0.3)	[5]	(1.2)	[5]	(0.4)	[5]
Depreciation and amortization	1.6	[5]	1.4	[5]	4.7	[5]	4.4	[5]
Capital expenditures	2.0	[5]	1.1	[5]	5.1	[5]	3.8	[5]
Total assets (at period end)	353.2	[5]	338.9	[5]	353.2	[5]	338.9	[5]
Goodwill (at period end)	$ 7.0	[5]	$ 7.0	[5]	$ 7.0	[5]	$ 7.0	[5]

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

[2] The following table provides a reconciliation of Partnership EBITDA to AmeriGas Propane operating income:Three Months Ended June 30, 2013 2012Partnership EBITDA $59.1 1.8Depreciation and amortization (52.5) (49.5)Gain on extinguishments of debt — (0.1)Noncontrolling interests (i) — (0.6)Operating income (loss) $6.6 $(48.4)(i)Principally represents the General Partner’s 1.01% interest in AmeriGas OLP.

[3] The following table provides a reconciliation of Partnership EBITDA to AmeriGas Propane operating income:Nine Months Ended June 30, 2013 2012Partnership EBITDA $550.5 $310.0Depreciation and amortization (150.5) (118.5)Loss on extinguishments of debt — 13.3Noncontrolling interests (i) 3.9 1.9Operating income $403.9 $206.7(i)Principally represents the General Partner’s 1.01% interest in AmeriGas OLP.

[4] Principally represents the General Partner’s 1.01% interest in AmeriGas OLP.

[5] Corporate & Other results principally comprise Electric Utility, Enterprises’ heating, ventilation, air-conditioning, refrigeration and electrical contracting businesses (“HVAC/R”), net expenses of UGI’s captive general liability insurance company and UGI’s unallocated corporate and general expenses and interest income. Corporate & Other assets principally comprise cash, short-term investments, the assets of Electric Utility and HVAC/R, and an intercompany loan. The intercompany loan and associated interest is removed in the segment presentation.