Segment Information - Schedule of Segment Reporting Information (Details) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Mar. 31, 2016	Mar. 31, 2015		Mar. 31, 2016	Mar. 31, 2015		Sep. 30, 2015
Segment Reporting Information
Revenues		$ 1,972.1	$ 2,455.6	[1]	$ 3,578.7	$ 4,460.2	[1]
Cost of sales		776.9	1,205.4	[1]	1,510.9	2,610.0	[1]
Segment profit:
Operating income (loss)		615.4	702.1	[1]	920.9	785.4	[1]
Loss from equity investees		0.0	(0.1)	[1]	(0.1)	(1.1)	[1]
Interest expense		(57.3)	(58.2)	[1]	(115.2)	(117.2)	[1]
Income before income taxes		558.1	643.8	[1]	805.6	667.1	[1]
Noncontrolling interests’ net income		174.8	235.7	[1]	228.1	201.8	[1]
Depreciation and amortization		100.7	88.0	[1]	201.3	179.0	[1]
Capital expenditures (including the effects of accruals)		114.5	91.4	[1]	247.4	214.9	[1]
Total assets		10,955.4	10,182.7	[1]	10,955.4	10,182.7	[1]	$ 10,546.6
Short-term borrowings		227.1	89.9	[1]	227.1	89.9	[1]	189.9
Goodwill		2,998.6	2,731.2	[1]	2,998.6	2,731.2	[1]	$ 2,953.4
AmeriGas Propane
Segment profit:
Operating income (loss)		250.4	296.9		380.0	436.6
Partnership Adjusted EBITDA		295.4	342.1		473.1	530.6
Depreciation and amortization		47.4	48.1		96.6	97.5
Eliminations
Segment Reporting Information
Revenues	[2]	(59.2)	(114.7)	[1]	(104.6)	(182.4)	[1]
Cost of sales	[2]	(58.5)	(114.0)	[1]	(103.0)	(181.0)	[1]
Segment profit:
Operating income (loss)		0.0	0.1	[1]	0.1	0.1	[1]
Loss from equity investees			0.0	[1]	0.0	0.0	[1]
Interest expense		0.0	0.0	[1]	0.0	0.0	[1]
Income before income taxes		0.0	0.1	[1]	0.1	0.1	[1]
Noncontrolling interests’ net income		0.0	0.0	[1]	0.0	0.0	[1]
Depreciation and amortization		(0.1)	(0.1)	[1]	(0.1)	0.0	[1]
Capital expenditures (including the effects of accruals)		0.0	0.0	[1]	0.0	0.0	[1]
Total assets		(87.5)	(109.5)	[1]	(87.5)	(109.5)	[1]
Short-term borrowings		0.0	0.0	[1]	0.0	0.0	[1]
Goodwill		0.0	0.0	[1]	0.0	0.0	[1]
Operating Segments | AmeriGas Propane
Segment Reporting Information
Revenues		827.5	1,100.3	[1]	1,471.6	1,989.1	[1]
Cost of sales		298.2	505.2	[1]	541.4	967.6	[1]
Segment profit:
Operating income (loss)		250.4	296.9	[1]	380.0	436.6	[1]
Loss from equity investees			0.0	[1]	0.0	0.0	[1]
Interest expense		(40.8)	(41.1)	[1]	(81.8)	(82.1)	[1]
Income before income taxes		209.6	255.8	[1]	298.2	354.5	[1]
Partnership Adjusted EBITDA	[3]	295.4	342.1	[1]	473.1	530.6	[1]
Noncontrolling interests’ net income		146.0	180.9	[1],[4]	203.3	247.7	[1],[4]
Depreciation and amortization		47.4	48.1	[1]	96.6	97.5	[1]
Capital expenditures (including the effects of accruals)		27.8	26.8	[1]	55.8	57.2	[1]
Total assets		4,201.1	4,423.8	[1]	4,201.1	4,423.8	[1]
Short-term borrowings		65.3	55.0	[1]	65.3	55.0	[1]
Goodwill		1,971.3	1,949.7	[1]	1,971.3	1,949.7	[1]
Operating Segments | UGI Utilities
Segment Reporting Information
Revenues		322.0	500.6	[1]	520.0	787.9	[1]
Cost of sales		137.5	278.3	[1]	212.9	421.4	[1]
Segment profit:
Operating income (loss)		114.5	142.7	[1]	162.8	218.3	[1]
Loss from equity investees			0.0	[1]	0.0	0.0	[1]
Interest expense		(9.3)	(10.7)	[1]	(18.8)	(21.3)	[1]
Income before income taxes		105.2	132.0	[1]	144.0	197.0	[1]
Noncontrolling interests’ net income		0.0	0.0	[1]	0.0	0.0	[1]
Depreciation and amortization		17.0	15.7	[1]	33.7	31.1	[1]
Capital expenditures (including the effects of accruals)		48.1	41.3	[1]	109.6	96.3	[1]
Total assets		2,641.6	2,506.0	[1]	2,641.6	2,506.0	[1]
Short-term borrowings		155.0	30.5	[1]	155.0	30.5	[1]
Goodwill		182.1	182.1	[1]	182.1	182.1	[1]
Operating Segments | Midstream & Marketing, Energy Services
Segment Reporting Information
Revenues		285.7	424.1	[1]	500.5	738.2	[1]
Cost of sales		186.1	305.5	[1]	337.3	550.1	[1]
Segment profit:
Operating income (loss)		76.1	91.1	[1]	117.4	137.4	[1]
Loss from equity investees			0.0	[1]	0.0	0.0	[1]
Interest expense		(0.5)	(0.5)	[1]	(1.3)	(1.1)	[1]
Income before income taxes		75.6	90.6	[1]	116.1	136.3	[1]
Noncontrolling interests’ net income		0.0	0.0	[1]	0.0	0.0	[1]
Depreciation and amortization		4.3	3.9	[1]	8.4	7.7	[1]
Capital expenditures (including the effects of accruals)		15.2	6.0	[1]	37.1	18.9	[1]
Total assets		723.0	719.6	[1]	723.0	719.6	[1]
Short-term borrowings		4.0	0.0	[1]	4.0	0.0	[1]
Goodwill		11.5	11.8	[1]	11.5	11.8	[1]
Operating Segments | Midstream & Marketing, Electric Generation
Segment Reporting Information
Revenues		15.8	24.8	[1]	30.6	41.3	[1]
Cost of sales		6.3	9.4	[1]	12.3	17.4	[1]
Segment profit:
Operating income (loss)		1.7	8.0	[1]	3.3	7.3	[1]
Loss from equity investees			0.0	[1]	0.0	0.0	[1]
Interest expense		0.0	0.0	[1]	0.0	0.0	[1]
Income before income taxes		1.7	8.0	[1]	3.3	7.3	[1]
Noncontrolling interests’ net income		0.0	0.0	[1]	0.0	0.0	[1]
Depreciation and amortization		3.4	3.3	[1]	6.7	6.0	[1]
Capital expenditures (including the effects of accruals)		1.1	2.3	[1]	1.6	8.9	[1]
Total assets		277.2	281.2	[1]	277.2	281.2	[1]
Short-term borrowings		0.0	0.0	[1]	0.0	0.0	[1]
Goodwill		0.0	0.0	[1]	0.0	0.0	[1]
Operating Segments | UGI International, UGI France
Segment Reporting Information
Revenues		446.7	347.2	[1]	855.4	685.1	[1]
Cost of sales		197.2	200.3	[1]	389.8	409.6	[1]
Segment profit:
Operating income (loss)		94.6	53.2	[1]	163.3	91.6	[1]
Loss from equity investees			(0.1)	[1]	(0.1)	(1.1)	[1]
Interest expense		(5.6)	(4.9)	[1]	(11.2)	(10.5)	[1]
Income before income taxes		89.0	48.2	[1]	152.0	80.0	[1]
Noncontrolling interests’ net income		0.1	0.3	[1]	0.2	0.4	[1]
Depreciation and amortization		23.3	11.8	[1]	44.9	25.1	[1]
Capital expenditures (including the effects of accruals)		17.3	9.6	[1]	33.6	21.7	[1]
Total assets		2,522.4	1,569.2	[1]	2,522.4	1,569.2	[1]
Short-term borrowings		1.6	0.1	[1]	1.6	0.1	[1]
Goodwill		734.5	510.9	[1]	734.5	510.9	[1]
Operating Segments | UGI International, Flaga & Other
Segment Reporting Information
Revenues		132.0	172.9	[1]	301.5	397.5	[1]
Cost of sales		73.8	123.3	[1]	184.0	295.9	[1]
Segment profit:
Operating income (loss)		16.9	11.5	[1]	33.3	26.6	[1]
Loss from equity investees			0.0	[1]	0.0	0.0	[1]
Interest expense		(0.9)	(0.9)	[1]	(1.8)	(1.9)	[1]
Income before income taxes		16.0	10.6	[1]	31.5	24.7	[1]
Noncontrolling interests’ net income		0.0	0.0	[1]	0.0	0.0	[1]
Depreciation and amortization		5.0	5.2	[1]	10.6	11.3	[1]
Capital expenditures (including the effects of accruals)		5.0	5.4	[1]	9.7	11.8	[1]
Total assets		551.7	539.7	[1]	551.7	539.7	[1]
Short-term borrowings		1.2	4.3	[1]	1.2	4.3	[1]
Goodwill		99.2	76.7	[1]	99.2	76.7	[1]
Corporate & Other
Segment Reporting Information
Revenues	[5]	1.6	0.4	[1]	3.7	3.5	[1]
Cost of sales	[5]	(63.7)	(102.6)	[1]	(63.8)	129.0	[1]
Segment profit:
Operating income (loss)	[5]	61.2	98.6	[1]	60.7	(132.5)	[1]
Loss from equity investees	[5]		0.0	[1]	0.0	0.0	[1]
Interest expense	[5]	(0.2)	(0.1)	[1]	(0.3)	(0.3)	[1]
Income before income taxes	[5]	61.0	98.5	[1]	60.4	(132.8)	[1]
Noncontrolling interests’ net income	[5]	28.7	54.5	[1],[4]	24.6	(46.3)	[1],[4]
Depreciation and amortization	[5]	0.4	0.1	[1]	0.5	0.3	[1]
Capital expenditures (including the effects of accruals)	[5]	0.0	0.0	[1]	0.0	0.1	[1]
Total assets	[5]	125.9	252.7	[1]	125.9	252.7	[1]
Short-term borrowings	[5]	0.0	0.0	[1]	0.0	0.0	[1]
Goodwill	[5]	0.0	0.0	[1]	0.0	0.0	[1]
Gains (losses) on unsettled commodity derivative instruments, net		$ 64.0	$ 102.2		$ 65.1	$ (127.5)

[1] Certain amounts have been restated to reflect the current-year changes in our segment presentation as described above.

[2] Represents the elimination of intersegment transactions principally among Midstream & Marketing, UGI Utilities and AmeriGas Propane.

[3] The following table provides a reconciliation of Partnership Adjusted EBITDA to AmeriGas Propane operating income: Three Months EndedMarch 31, Six Months Ended March 31, 2016 2015 2016 2015Partnership Adjusted EBITDA $295.4 $342.1 $473.1 $530.6Depreciation and amortization (47.4) (48.1) (96.6) (97.5)Noncontrolling interests (i) 2.4 2.9 3.5 3.5Operating income $250.4 $296.9 $380.0 $436.6(i)Principally represents the General Partner’s 1.01% interest in AmeriGas OLP.

[4] Amounts for AmeriGas Propane and Corporate & Other have been corrected to properly reflect gains and (losses) on commodity derivative instruments not associated with current period transactions.

[5] Corporate & Other results principally comprise (1) net expenses of UGI’s captive general liability insurance company, and (2) UGI Corporation’s unallocated corporate and general expenses and interest income. In addition, Corporate & Other results also include the effects of net pre-tax gains and (losses) on commodity derivative instruments not associated with current-period transactions totaling $64.0 and $102.2 during the three months ended March 31, 2016 and 2015, respectively, and $65.1 and $(127.5) during the six months ended March 31, 2016 and 2015, respectively. Corporate & Other assets principally comprise cash and short-term investments of UGI and its captive insurance company; UGI corporate headquarters’ assets; and our investment in a private equity partnership.