Segment Information - Schedule of Segment Reporting Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Mar. 31, 2015		Mar. 31, 2014		Mar. 31, 2015		Mar. 31, 2014		Sep. 30, 2014
Segment Reporting Information
Revenues	$ 2,455.6		$ 3,163.3		$ 4,460.2		$ 5,479.2
Cost of sales	1,205.4		2,001.3		2,610.0		3,431.2
Segment profit:
Operating income	702.1		588.6		785.4		952.3
Loss from equity investees	(0.1)		0		(1.1)		0
Interest expense	(58.2)		(59.5)		(117.2)		(118.8)
Income before income taxes	643.8		529.1		667.1		833.5
Noncontrolling interests’ net income	235.7		173.4		201.8		268.9
Depreciation and amortization	88.0		87.7		179.0		181.7
Capital expenditures	(91.4)		(85.3)		(214.9)		(188.1)
Total assets	10,182.7		10,720.5		10,182.7		10,720.5		10,093.0
Short-term borrowings	89.9		260.1		89.9		260.1		210.8
Goodwill	2,731.2		2,886.0		2,731.2		2,886.0		2,833.4
Gains (losses) on unsettled commodity derivative instruments, net	102.2		(13.2)		(127.5)		(6.0)
Eliminations
Segment Reporting Information
Revenues	(114.7)	[1]	(164.7)	[1]	(182.4)	[1]	(230.2)	[1]
Cost of sales	(114.0)	[1]	(164.0)	[1]	(181.0)	[1]	(228.4)	[1]
Segment profit:
Operating income	0.1		0.2		0.1		0.1
Loss from equity investees	0		0		0		0
Interest expense	0		0		0		0
Income before income taxes	0.1		0.2		0.1		0.1
Noncontrolling interests’ net income	0		0		0		0
Depreciation and amortization	(0.1)		(0.1)		(0.1)		(0.1)
Capital expenditures	0		0		0		1.2
Total assets	(109.5)		(116.3)		(109.5)		(116.3)
Short-term borrowings	0		0		0		0
Goodwill	0		0		0		0
AmeriGas Propane
Segment Reporting Information
Revenues	1,100.3		1,493.7		1,989.1		2,539.5
Cost of sales	505.2		885.5		967.6		1,468.2
Segment profit:
Operating income	296.9		284.8		436.6		464.5
Loss from equity investees	0		0		0		0
Interest expense	(41.1)		(42.0)		(82.1)		(83.6)
Income before income taxes	255.8		242.8		354.5		380.9
Partnership Adjusted EBITDA	342.1	[2]	331.2	[2]	530.6	[2]	561.5	[2]
Noncontrolling interests’ net income	88.3		173.2		155.1		268.6
Depreciation and amortization	48.1		49.2		97.5		101.5
Capital expenditures	(26.8)		(27.7)		(57.2)		(51.0)
Total assets	4,423.8		4,692.3		4,423.8		4,692.3
Short-term borrowings	55.0		198.0		55.0		198.0
Goodwill	1,949.7		1,939.0		1,949.7		1,939.0
Noncontrolling interests	2.9	[3]	2.8	[3]	3.5	[3]	4.5	[3]
Gas Utility
Segment Reporting Information
Revenues	468.0		480.1		728.5		751.7
Cost of sales	258.2		278.8		385.4		414.3
Segment profit:
Operating income	139.3		134.5		211.1		216.6
Loss from equity investees	0		0		0		0
Interest expense	(10.1)		(8.4)		(20.2)		(16.8)
Income before income taxes	129.2		126.1		190.9		199.8
Noncontrolling interests’ net income	0		0		0		0
Depreciation and amortization	14.5		13.6		28.8		27.0
Capital expenditures	(39.2)		(30.0)		(92.7)		(62.9)
Total assets	2,359.1		2,195.4		2,359.1		2,195.4
Short-term borrowings	30.5		6.5		30.5		6.5
Goodwill	182.1		182.1		182.1		182.1
Midstream & Marketing, Energy Services
Segment Reporting Information
Revenues	409.4		588.9		706.4		861.6
Cost of sales	296.5		457.9		530.9		685.0
Segment profit:
Operating income	93.9		111.5		140.1		143.3
Loss from equity investees	0		0		0		0
Interest expense	(0.5)		(1.0)		(1.1)		(2.0)
Income before income taxes	93.4		110.5		139.0		141.3
Noncontrolling interests’ net income	0		0		0		0
Depreciation and amortization	3.6		3.2		7.2		5.8
Capital expenditures	(5.9)		(8.4)		(18.7)		(30.1)
Total assets	690.8		643.2		690.8		643.2
Short-term borrowings	0		51.5		0		51.5
Goodwill	5.6		2.8		5.6		2.8
Midstream & Marketing, Electric Generation
Segment Reporting Information
Revenues	24.8		25.1		41.3		45.9
Cost of sales	9.4		9.4		17.4		20.0
Segment profit:
Operating income	8.0		9.9		7.3		14.3
Loss from equity investees	0		0		0		0
Interest expense	0		0		0		0
Income before income taxes	8.0		9.9		7.3		14.3
Noncontrolling interests’ net income	0		0		0		0
Depreciation and amortization	3.3		2.7		6.0		5.3
Capital expenditures	(2.3)		(1.8)		(8.9)		(11.1)
Total assets	281.2		283.9		281.2		283.9
Short-term borrowings	0		0		0		0
Goodwill	0		0		0		0
UGI International, Antargaz
Segment Reporting Information
Revenues	347.2		412.0		685.1		837.3
Cost of sales	200.3		266.7		409.6		549.2
Segment profit:
Operating income	53.2		52.9		91.6		96.1
Loss from equity investees	(0.1)		0		(1.1)		0
Interest expense	(4.9)		(6.4)		(10.5)		(12.8)
Income before income taxes	48.2		46.5		80.0		83.3
Noncontrolling interests’ net income	0.3		0.2		0.4		0.3
Depreciation and amortization	11.8		10.3		25.1		25.3
Capital expenditures	(9.6)		(11.3)		(21.7)		(21.1)
Total assets	1,569.2		1,923.2		1,569.2		1,923.2
Short-term borrowings	0.1		0		0.1		0
Goodwill	510.9		655.3		510.9		655.3
UGI International, Flaga & Other
Segment Reporting Information
Revenues	172.9		277.2		397.5		570.5
Cost of sales	123.3		222.7		295.9		454.4
Segment profit:
Operating income	11.5		10.9		26.6		24.6
Loss from equity investees	0		0		0		0
Interest expense	(0.9)		(1.1)		(1.9)		(2.4)
Income before income taxes	10.6		9.8		24.7		22.2
Noncontrolling interests’ net income	0		0		0		0
Depreciation and amortization	5.2		7.2		11.3		13.8
Capital expenditures	(5.4)		(4.2)		(11.8)		(8.8)
Total assets	539.7		660.4		539.7		660.4
Short-term borrowings	4.3		4.1		4.3		4.1
Goodwill	76.7		99.8		76.7		99.8
Corporate & Other
Segment Reporting Information
Revenues	47.7	[4]	51.0	[4]	94.7	[4]	102.9	[4]
Cost of sales	(73.5)	[4]	44.3	[4]	184.2	[4]	68.5	[4]
Segment profit:
Operating income	99.2	[4]	(16.1)	[4]	(128.0)	[4]	(7.2)	[4]
Loss from equity investees	0	[4]	0	[4]	0	[4]	0	[4]
Interest expense	(0.7)	[4]	(0.6)	[4]	(1.4)	[4]	(1.2)	[4]
Income before income taxes	98.5	[4]	(16.7)	[4]	(129.4)	[4]	(8.4)	[4]
Noncontrolling interests’ net income	147.1	[4]	0	[4]	46.3	[4]	0	[4]
Depreciation and amortization	1.6	[4]	1.6	[4]	3.2	[4]	3.1	[4]
Capital expenditures	(2.2)	[4]	(1.9)	[4]	(3.9)	[4]	(4.3)	[4]
Total assets	428.4	[4]	438.4	[4]	428.4	[4]	438.4	[4]
Short-term borrowings	0	[4]	0	[4]	0	[4]	0	[4]
Goodwill	$ 6.2	[4]	$ 7.0	[4]	$ 6.2	[4]	$ 7.0	[4]

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

[2] The following table provides a reconciliation of Partnership Adjusted EBITDA to AmeriGas Propane operating income: Three Months EndedMarch 31, Six Months Ended March 31, 2015 2014 2015 2014Partnership Adjusted EBITDA $342.1 $331.2 $530.6 $561.5Depreciation and amortization (48.1) (49.2) (97.5) (101.5)Noncontrolling interests (i) 2.9 2.8 3.5 4.5Operating income $296.9 $284.8 $436.6 $464.5(i)Principally represents the General Partner’s 1.01% interest in AmeriGas OLP.

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

[4] Corporate & Other results principally comprise (1) Electric Utility, (2) Enterprises’ heating, ventilation, air-conditioning, refrigeration and electrical contracting businesses (“HVAC”), (3) net expenses of UGI’s captive general liability insurance company, and (4) UGI Corporation’s unallocated corporate and general expenses and interest income. In addition, Corporate & Other results also include net gains and (losses) on commodity derivative instruments not associated with current-period transactions totaling $102.2 and $(13.2) during the three months ended March 31, 2015 and 2014, respectively, and $(127.5) and $(6.0) during the six months ended March 31, 2015 and 2014, respectively. Corporate & Other assets principally comprise cash, short-term investments, the assets of Electric Utility and HVAC, and, in the three and six months ended March 31, 2014, an intercompany loan. The intercompany loan and associated interest is removed in the segment presentation.