Segment Information - Schedule of Segment Reporting Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013		Sep. 30, 2013
Segment Reporting Information
Revenues	$ 1,486.7		$ 1,374.3		$ 6,965.9		$ 5,935.7
Cost of sales	926.5		836.8		4,357.7		3,539.0
Segment profit:
Operating income (loss)	62.7		41.5		1,015.0		843.4
(Loss) income from equity investees	(0.1)		0		(0.1)		0.1
Interest expense	(60.1)		(59.2)		(178.9)		(180.8)
Income (loss) before income taxes	2.5		(17.7)		836.0		662.7
Partnership EBITDA	52.2	[1]			613.7	[2]	557.1	[2]
Noncontrolling interests’ net (loss) income	(33.3)		(31.9)		235.6		194.4
Depreciation and amortization	90.0		91.8		271.7		269.2
Capital expenditures	102.4		107.6		290.5		292.5
Total assets (at period end)	10,077.7		9,806.8		10,077.7		9,806.8		10,008.8
Bank loans (at period end)	96.5		135.9		96.5		135.9		227.9
Goodwill (at period end)	2,885.1		2,834.0		2,885.1		2,834.0		2,871.0
Limited Liability Company or Limited Partnership Managing Member or General Partner Ownership Interest Percentage	1.01%
Eliminations
Segment Reporting Information
Revenues	(50.8)	[3]	(61.5)	[3]	(281.0)	[3]	(181.1)	[3]
Cost of sales	(49.6)	[3]	(60.1)	[3]	(278.0)	[3]	(176.2)	[3]
Segment profit:
Operating income (loss)	(0.1)		(0.2)		0		(1.1)
(Loss) income from equity investees	0		0		0		0
Interest expense	0		0		0		0
Income (loss) before income taxes	(0.1)		(0.2)		0		(1.1)
Noncontrolling interests’ net (loss) income	0		0		0		0
Depreciation and amortization	0		(0.1)		(0.1)		(0.1)
Capital expenditures	1.2		(0.1)		0		(1.1)
Total assets (at period end)	(112.8)		(95.9)		(112.8)		(95.9)
Bank loans (at period end)	0		0		0		0
Goodwill (at period end)	0		0		0		0
AmeriGas Propane
Segment Reporting Information
Revenues	613.2		581.7		3,152.7		2,636.9
Cost of sales	340.8		305.7		1,809.0		1,367.4
Segment profit:
Operating income (loss)	7.2		3.8		471.7		407.5
(Loss) income from equity investees	0		0		0		0
Interest expense	(41.4)		(41.2)		(125.0)		(125.4)
Income (loss) before income taxes	(34.2)		(37.4)		346.7		282.1
Partnership EBITDA	55.0	[1]	56.3	[1]	616.5	[2]	557.1
Noncontrolling interests’ net (loss) income	(31.0)		(31.7)		237.6		194.2
Depreciation and amortization	47.8		52.4		149.3		153.4
Capital expenditures	29.3		26.3		80.3		80.7
Total assets (at period end)	4,345.8		4,386.8		4,345.8		4,386.8
Bank loans (at period end)	92.5		80.0		92.5		80.0
Goodwill (at period end)	1,939.0		1,929.2		1,939.0		1,929.2
Noncontrolling Interests Principally General Partners Interest in Related Parties	0	[4]	(0.1)	[4]	4.5	[4]	3.8	[4]
Gas Utility
Segment Reporting Information
Revenues	128.3		126.7		880.0		743.6
Cost of sales	49.2		52.4		463.5		372.7
Segment profit:
Operating income (loss)	17.1		14.2		233.7		189.7
(Loss) income from equity investees	0		0		0		0
Interest expense	(9.8)		(9.2)		(26.6)		(28.1)
Income (loss) before income taxes	7.3		5.0		207.1		161.6
Noncontrolling interests’ net (loss) income	0		0		0		0
Depreciation and amortization	13.7		13.1		40.7		38.4
Capital expenditures	35.9		37.3		98.8		90.2
Total assets (at period end)	2,147.4		2,143.7		2,147.4		2,143.7
Bank loans (at period end)	0		0		0		0
Goodwill (at period end)	182.1		182.1		182.1		182.1
Midstream & Marketing, Energy Services
Segment Reporting Information
Revenues	248.3		233.0		1,109.9		764.8
Cost of sales	209.2		214.9		894.2		650.5
Segment profit:
Operating income (loss)	23.5		6.4		166.8		76.5
(Loss) income from equity investees	0		0		0		0
Interest expense	(0.5)		(0.6)		(2.5)		(2.4)
Income (loss) before income taxes	23.0		5.8		164.3		74.1
Noncontrolling interests’ net (loss) income	0		0		0		0
Depreciation and amortization	3.3		2.1		9.1		5.6
Capital expenditures	11.2		22.0		41.3		54.8
Total assets (at period end)	542.7		437.0		542.7		437.0
Bank loans (at period end)	0		45.5		0		45.5
Goodwill (at period end)	5.6		2.8		5.6		2.8
Midstream & Marketing, Electric Generation
Segment Reporting Information
Revenues	20.5		16.3		66.4		48.7
Cost of sales	10.5		8.5		30.5		29.0
Segment profit:
Operating income (loss)	2.6		0.6		16.9		1.4
(Loss) income from equity investees	0		0		0		0
Interest expense	0		0		0		0
Income (loss) before income taxes	2.6		0.6		16.9		1.4
Noncontrolling interests’ net (loss) income	0		0		0		0
Depreciation and amortization	2.7		2.6		8.0		7.5
Capital expenditures	1.9		4.4		13.0		15.4
Total assets (at period end)	279.1		267.2		279.1		267.2
Bank loans (at period end)	0		0		0		0
Goodwill (at period end)	0		0		0		0
International Propane, Antargaz
Segment Reporting Information
Revenues	249.2		249.3		1,086.5		1,121.2
Cost of sales	164.1		148.7		713.3		714.4
Segment profit:
Operating income (loss)	(1.4)		14.6		94.7		129.9
(Loss) income from equity investees	(0.1)		0		(0.1)		0.1
Interest expense	(6.3)		(6.2)		(19.1)		(19.0)
Income (loss) before income taxes	(7.8)		8.4		75.5		111.0
Noncontrolling interests’ net (loss) income	(0.3)		(0.3)		0		0.1
Depreciation and amortization	14.6		14.0		39.9		42.3
Capital expenditures	15.6		11.7		36.7		37.1
Total assets (at period end)	1,784.2		1,771.7		1,784.2		1,771.7
Bank loans (at period end)	0		0		0		0
Goodwill (at period end)	651.7		619.2		651.7		619.2
International Propane, Flaga & Other
Segment Reporting Information
Revenues	232.3		182.5		802.8		659.0
Cost of sales	180.7		134.8		635.1		507.1
Segment profit:
Operating income (loss)	8.2		6.5		32.8		30.6
(Loss) income from equity investees	0		0		0		0
Interest expense	(1.4)		(1.2)		(3.8)		(3.8)
Income (loss) before income taxes	6.8		5.3		29.0		26.8
Noncontrolling interests’ net (loss) income	0		0.1		0		0.1
Depreciation and amortization	6.2		6.1		20.0		17.4
Capital expenditures	4.8		4.0		13.6		10.3
Total assets (at period end)	650.6		543.1		650.6		543.1
Bank loans (at period end)	4.0		10.4		4.0		10.4
Goodwill (at period end)	99.7		93.7		99.7		93.7
Corporate & Other
Segment Reporting Information
Revenues	45.7	[5]	46.3	[5]	148.6	[6]	142.6	[6]
Cost of sales	21.6	[5]	31.9	[5]	90.1	[6]	74.1	[6]
Segment profit:
Operating income (loss)	5.6	[5]	(4.4)	[5]	(1.6)	[6]	8.9	[6]
(Loss) income from equity investees	0	[5]	0	[5]	0	[6]	0	[6]
Interest expense	(0.7)	[5]	(0.8)	[5]	(1.9)	[6]	(2.1)	[6]
Income (loss) before income taxes	4.9	[5]	(5.2)	[5]	(3.5)	[6]	6.8	[6]
Partnership EBITDA	(2.8)	[1]			(2.8)	[2]
Noncontrolling interests’ net (loss) income	(2.0)	[5]	0	[5]	(2.0)	[6]	0	[6]
Depreciation and amortization	1.7	[5]	1.6	[5]	4.8	[6]	4.7	[6]
Capital expenditures	2.5	[5]	2.0	[5]	6.8	[6]	5.1
Total assets (at period end)	440.7	[5],[6]	353.2	[5],[6]	440.7	[5],[6]	353.2	[5],[6]
Bank loans (at period end)	0	[5],[6]	0	[5],[6]	0	[5],[6]	0	[5],[6]
Goodwill (at period end)	$ 7.0	[5],[6]	$ 7.0	[5],[6]	$ 7.0	[5],[6]	$ 7.0	[5],[6]

[1] The following table provides a reconciliation of Partnership EBITDA to AmeriGas Propane operating income:Three Months Ended June 30, 2014 2013Partnership EBITDA $55.0 $56.3Depreciation and amortization (47.8) (52.4)Noncontrolling interests (i) — (0.1)Operating income $7.2 $3.8(i)Principally represents the General Partner’s 1.01% interest in AmeriGas OLP.

[2] The following table provides a reconciliation of Partnership EBITDA to AmeriGas Propane operating income:Nine Months Ended June 30, 2014 2013Partnership EBITDA $616.5 $557.1Depreciation and amortization (149.3) (153.4)Noncontrolling interests (i) 4.5 3.8Operating income $471.7 $407.5(i)Principally represents the General Partner’s 1.01% interest in AmeriGas OLP.

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

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

[5] Corporate & Other results principally comprise (1) Electric Utility, (2) Enterprises’ heating, ventilation, air-conditioning, refrigeration and electrical contracting businesses (“HVAC”), (3) net gains and losses on Midstream & Marketing’s commodity derivative instruments, and net gains and losses on AmeriGas Propane’s commodity derivative instruments entered into beginning April 1, 2014, that are not associated with current period transactions, (4) net expenses of UGI’s captive general liability insurance company, and (5) UGI Corporation’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, and an intercompany loan. The intercompany loan and associated interest is removed in the segment presentation.

[6] .