Segment Information - Partnership EBITDA (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Mar. 31, 2014		Mar. 31, 2013		Sep. 30, 2013
Segment Reporting Information
Revenues	$ 3,163.3		$ 2,542.7		$ 5,479.2		$ 4,561.4
Cost of sales	2,001.3		1,486.7		3,431.2		2,702.2
Segment profit:
Operating income (loss)	588.6		507.7		952.3		801.9
Income from equity investees	0		0.1		0		0.1
Interest expense	(59.5)		(60.1)		(118.8)		(121.6)
Income (loss) before income taxes	529.1		447.7		833.5		680.4
Partnership EBITDA							500.8	[1]
Noncontrolling interests' net income (loss)	173.4		161.0		268.9		226.3
Depreciation and amortization	87.7		89.6		181.7		177.4
Capital expenditures	85.3		93.6		188.1		184.8
Total assets (at period end)	10,720.5		10,215.4		10,720.5		10,215.4		10,008.8
Bank loans (at period end)	260.1		177.7		260.1		177.7		227.9
Goodwill (at period end)	2,886.0		2,813.8		2,886.0		2,813.8		2,871.0
Eliminations
Segment Reporting Information
Revenues	(164.7)	[2]	(61.1)	[2]	(230.2)	[2]	(119.6)	[2]
Cost of sales	(164.0)	[2]	(58.8)	[2]	(228.4)	[2]	(116.1)	[2]
Segment profit:
Operating income (loss)	0.2		(0.9)		0.1		(0.9)
Income from equity investees	0		0		0		0
Interest expense	0		0		0		0
Income (loss) before income taxes	0.2		(0.9)		0.1		(0.9)
Noncontrolling interests' net income (loss)	0		0		0		0
Depreciation and amortization	(0.1)		0		(0.1)		0
Capital expenditures	0		(1.0)		(1.2)		(1.1)
Total assets (at period end)	(116.3)		(110.8)		(116.3)		(110.8)
Bank loans (at period end)	0		0		0		0
Goodwill (at period end)	0		0		0		0
AmeriGas Propane
Segment Reporting Information
Revenues	1,493.7		1,183.3		2,539.5		2,055.2
Cost of sales	885.5		612.4		1,468.2		1,061.7
Segment profit:
Operating income (loss)	284.8		266.4		464.5		403.7
Income from equity investees	0		0		0		0
Interest expense	(42.0)		(41.8)		(83.6)		(84.2)
Income (loss) before income taxes	242.8		224.6		380.9		319.5
Partnership EBITDA	331.3	[3]	314.9	[3]	561.5	[1]	500.8
Noncontrolling interests' net income (loss)	173.2		160.7		268.6		225.9
Depreciation and amortization	49.2		50.9		101.5		101.0
Capital expenditures	27.7		27.9		51.0		54.4
Total assets (at period end)	4,692.3		4,682.6		4,692.3		4,682.6
Bank loans (at period end)	198.0		115.9		198.0		115.9
Goodwill (at period end)	1,939.0		1,919.2		1,939.0		1,919.2
Noncontrolling Interests Principally General Partners Interest in Related Parties	2.7	[4]	2.4	[4]	4.5	[4]	3.9	[4]
Gas Utility
Segment Reporting Information
Revenues	480.1		368.6		751.7		616.9
Cost of sales	278.8		196.7		414.3		320.3
Segment profit:
Operating income (loss)	134.5		105.7		216.6		175.5
Income from equity investees	0		0		0		0
Interest expense	(8.4)		(9.3)		(16.8)		(18.9)
Income (loss) before income taxes	126.1		96.4		199.8		156.6
Noncontrolling interests' net income (loss)	0		0		0		0
Depreciation and amortization	13.6		12.7		27.0		25.3
Capital expenditures	30.0		24.4		62.9		52.9
Total assets (at period end)	2,195.4		2,184.8		2,195.4		2,184.8
Bank loans (at period end)	6.5		0		6.5		0
Goodwill (at period end)	182.1		182.1		182.1		182.1
Midstream & Marketing, Energy Services
Segment Reporting Information
Revenues	588.9		304.0		861.6		531.8
Cost of sales	457.9		246.1		685.0		435.6
Segment profit:
Operating income (loss)	111.5		44.4		143.3		70.1
Income from equity investees	0		0		0		0
Interest expense	(1.0)		(0.8)		(2.0)		(1.8)
Income (loss) before income taxes	110.5		43.6		141.3		68.3
Noncontrolling interests' net income (loss)	0		0		0		0
Depreciation and amortization	3.2		1.9		5.8		3.5
Capital expenditures	8.4		19.3		30.1		32.8
Total assets (at period end)	643.2		450.4		643.2		450.4
Bank loans (at period end)	51.5		47.0		51.5		47.0
Goodwill (at period end)	2.8		2.8		2.8		2.8
Midstream & Marketing, Electric Generation
Segment Reporting Information
Revenues	25.1		17.4		45.9		32.4
Cost of sales	9.4		10.9		20.0		20.5
Segment profit:
Operating income (loss)	9.9		0.6		14.3		0.8
Income from equity investees	0		0		0		0
Interest expense	0		0		0		0
Income (loss) before income taxes	9.9		0.6		14.3		0.8
Noncontrolling interests' net income (loss)	0		0		0		0
Depreciation and amortization	2.7		2.4		5.3		4.9
Capital expenditures	1.8		4.2		11.1		11.0
Total assets (at period end)	283.9		261.7		283.9		261.7
Bank loans (at period end)	0		0		0		0
Goodwill (at period end)	0		0		0		0
International Propane, Antargaz
Segment Reporting Information
Revenues	412.0		452.6		837.3		871.9
Cost of sales	266.7		285.8		549.2		565.7
Segment profit:
Operating income (loss)	52.9		67.8		96.1		115.3
Income from equity investees	0		0.1		0		0.1
Interest expense	(6.4)		(6.3)		(12.8)		(12.8)
Income (loss) before income taxes	46.5		61.6		83.3		102.6
Noncontrolling interests' net income (loss)	0.2		0.3		0.3		0.4
Depreciation and amortization	10.3		14.2		25.3		28.3
Capital expenditures	11.3		13.2		21.1		25.4
Total assets (at period end)	1,923.2		1,847.7		1,923.2		1,847.7
Bank loans (at period end)	0		0		0		0
Goodwill (at period end)	655.3		610.0		655.3		610.0
International Propane, Flaga & Other
Segment Reporting Information
Revenues	277.2		230.9		570.5		476.5
Cost of sales	222.7		177.4		454.4		372.3
Segment profit:
Operating income (loss)	10.9		13.8		24.6		24.1
Income from equity investees	0		0		0		0
Interest expense	(1.1)		(1.3)		(2.4)		(2.6)
Income (loss) before income taxes	9.8		12.5		22.2		21.5
Noncontrolling interests' net income (loss)	0		0		0		0
Depreciation and amortization	7.2		5.8		13.8		11.3
Capital expenditures	4.2		4.1		8.8		6.3
Total assets (at period end)	660.4		551.3		660.4		551.3
Bank loans (at period end)	4.1		14.8		4.1		14.8
Goodwill (at period end)	99.8		92.7		99.8		92.7
Corporate & Other
Segment Reporting Information
Revenues	51.0	[5]	47.0	[5]	102.9	[6]	96.3	[6]
Cost of sales	44.3	[5]	16.2	[5]	68.5	[6]	42.2	[6]
Segment profit:
Operating income (loss)	(16.1)	[5]	9.9	[5]	(7.2)	[6]	13.3	[6]
Income from equity investees	0	[5]	0	[5]	0	[6]	0	[6]
Interest expense	(0.6)	[5]	(0.6)	[5]	(1.2)	[6]	(1.3)	[6]
Income (loss) before income taxes	(16.7)	[5]	9.3	[5]	(8.4)	[6]	12.0	[6]
Noncontrolling interests' net income (loss)	0	[5]	0	[5]	0	[6]	0	[6]
Depreciation and amortization	1.6	[5]	1.7	[5]	3.1	[6]	3.1	[6]
Capital expenditures	1.9	[5]	1.5	[5]	4.3	[6]	3.1	[6]
Total assets (at period end)	438.4	[5],[6]	347.7	[5],[6]	438.4	[5],[6]	347.7	[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:Six Months Ended March 31, 2014 2013Partnership EBITDA $561.5 $500.8Depreciation and amortization (101.5) (101.0)Noncontrolling interests (i) 4.5 3.9Operating income $464.5 $403.7(i)Principally represents the General Partner’s 1.01% interest in AmeriGas OLP.

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

[3] The following table provides a reconciliation of Partnership EBITDA to AmeriGas Propane operating income:Three Months Ended March 31, 2014 2013Partnership EBITDA $331.3 $314.9Depreciation and amortization (49.2) (50.9)Noncontrolling interests (i) 2.7 2.4Operating income $284.8 $266.4(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 (1) Electric Utility, (2) Enterprises’ heating, ventilation, air-conditioning, refrigeration and electrical contracting businesses (“HVAC”), (3) changes in the fair values of Midstream & Marketing’s unsettled commodity derivative instruments and gains and losses on settled commodity derivative instruments 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] Corporate & Other results principally comprise (1) Electric Utility, (2) HVAC, (3) changes in the fair values of Midstream & Marketing’s unsettled commodity derivative instruments and gains and losses on settled commodity derivative instruments 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.