Segment Information - Schedule of Segment Reporting Information (Details) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Mar. 31, 2017	Mar. 31, 2016		Mar. 31, 2017	Mar. 31, 2016		Sep. 30, 2016
Segment Reporting Information
Revenues		$ 2,173.8	$ 1,972.1	[1]	$ 3,853.3	$ 3,578.7	[1]
Cost of sales		1,071.2	776.9	[1]	1,718.6	1,510.9	[1]
Segment profit:
Operating income		513.2	615.4	[1]	979.4	920.9	[1]
Income (loss) from equity investees		2.3	0.0		2.1	(0.1)	[1]
(Losses) gains on foreign currency contracts, net		(1.2)	0.0		0.1	0.0
Loss on extinguishments of debt		(22.1)	0.0		(55.3)	0.0
Interest expense		(55.8)	(57.3)	[1]	(111.2)	(115.2)	[1]
Income before income taxes		436.4	558.1	[1]	815.1	805.6	[1]
Noncontrolling interests’ net income (loss)		91.9	174.8	[1]	152.1	228.1	[1]
Depreciation and amortization		99.3	100.7	[1]	197.4	201.3	[1]
Capital expenditures (including the effects of accruals)		126.2	114.5	[1]	299.8	247.4	[1]
Total assets		11,385.5	10,925.8	[1]	11,385.5	10,925.8	[1]	$ 10,847.2
Short-term borrowings		50.1	227.1	[1]	50.1	227.1	[1]	291.7
Goodwill		2,948.4	2,998.6	[1]	2,948.4	2,998.6	[1]	$ 2,989.0
Eliminations
Segment Reporting Information
Revenues	[2]	(95.8)	(56.5)	[1]	(164.3)	(99.2)	[1]
Cost of sales	[2]	(94.9)	(55.8)	[1]	(162.6)	(97.6)	[1]
Segment profit:
Operating income		0.0	0.0	[1]	0.1	0.1	[1]
Income (loss) from equity investees		0.0			0.0	0.0	[1]
(Losses) gains on foreign currency contracts, net		0.0			0.0
Loss on extinguishments of debt		0.0			0.0
Interest expense		0.0	0.0	[1]	0.0	0.0	[1]
Income before income taxes		0.0	0.0	[1]	0.1	0.1	[1]
Noncontrolling interests’ net income (loss)		0.0	0.0	[1]	0.0	0.0	[1]
Depreciation and amortization		(0.1)	(0.1)	[1]	(0.1)	(0.1)	[1]
Capital expenditures (including the effects of accruals)		0.0	0.0	[1]	0.0	0.0	[1]
Total assets		(58.6)	(87.5)	[1]	(58.6)	(87.5)	[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		863.6	827.5	[1]	1,540.8	1,471.6	[1]
Cost of sales		355.8	298.2	[1]	616.5	541.4	[1]
Segment profit:
Operating income		227.3	250.4	[1]	369.2	380.0	[1]
Income (loss) from equity investees		0.0			0.0	0.0	[1]
(Losses) gains on foreign currency contracts, net		0.0			0.0
Loss on extinguishments of debt		(22.1)	0.0		(55.3)	0.0
Interest expense		(40.0)	(40.8)	[1]	(80.0)	(81.8)	[1]
Income before income taxes		165.2	209.6	[1]	233.9	298.2	[1]
Partnership Adjusted EBITDA	[3]	271.2	295.4	[1]	456.3	473.1	[1]
Noncontrolling interests’ net income (loss)		112.7	146.0	[1]	153.9	203.3	[1]
Depreciation and amortization		45.0	47.4	[1]	89.6	96.6	[1]
Capital expenditures (including the effects of accruals)		27.2	27.8	[1]	53.6	55.8	[1]
Total assets		4,238.1	4,181.6	[1]	4,238.1	4,181.6	[1]
Short-term borrowings		0.0	65.3	[1]	0.0	65.3	[1]
Goodwill		1,981.2	1,971.3	[1]	1,981.2	1,971.3	[1]
Operating Segments | UGI International
Segment Reporting Information
Revenues		620.7	578.7	[1]	1,159.8	1,156.9	[1]
Cost of sales		313.1	271.0	[1]	571.1	573.8	[1]
Segment profit:
Operating income		121.0	111.5	[1]	209.9	196.6	[1]
Income (loss) from equity investees		(0.1)			(0.3)	(0.1)	[1]
(Losses) gains on foreign currency contracts, net		0.1			0.2
Loss on extinguishments of debt		0.0			0.0
Interest expense		(4.8)	(6.5)	[1]	(9.6)	(13.0)	[1]
Income before income taxes		116.2	105.0	[1]	200.2	183.5	[1]
Noncontrolling interests’ net income (loss)		0.1	0.1	[1]	0.3	0.2	[1]
Depreciation and amortization		27.6	28.3	[1]	55.5	55.5	[1]
Capital expenditures (including the effects of accruals)		21.5	22.3	[1]	43.0	43.3	[1]
Total assets		2,804.7	3,066.2	[1]	2,804.7	3,066.2	[1]
Short-term borrowings		1.6	2.8	[1]	1.6	2.8	[1]
Goodwill		773.6	833.7	[1]	773.6	833.7	[1]
Operating Segments | Midstream & Marketing
Segment Reporting Information
Revenues		423.7	298.8	[1]	693.5	525.7	[1]
Cost of sales		309.8	189.7	[1]	501.6	344.2	[1]
Segment profit:
Operating income		82.1	77.8	[1]	131.8	120.7	[1]
Income (loss) from equity investees		2.4			2.4	0.0	[1]
(Losses) gains on foreign currency contracts, net		0.0			0.0
Loss on extinguishments of debt		0.0			0.0
Interest expense		(0.7)	(0.5)	[1]	(1.3)	(1.3)	[1]
Income before income taxes		83.8	77.3	[1]	132.9	119.4	[1]
Noncontrolling interests’ net income (loss)		0.0	0.0	[1]	0.0	0.0	[1]
Depreciation and amortization		8.8	7.7	[1]	16.8	15.1	[1]
Capital expenditures (including the effects of accruals)		20.8	16.3	[1]	82.3	38.7	[1]
Total assets		1,200.7	1,000.2	[1]	1,200.7	1,000.2	[1]
Short-term borrowings		0.0	4.0	[1]	0.0	4.0	[1]
Goodwill		11.5	11.5	[1]	11.5	11.5	[1]
Operating Segments | UGI Utilities
Segment Reporting Information
Revenues		360.0	322.0	[1]	621.4	520.0	[1]
Cost of sales		164.5	137.5	[1]	274.0	212.9	[1]
Segment profit:
Operating income		116.4	114.5	[1]	198.6	162.8	[1]
Income (loss) from equity investees		0.0			0.0	0.0	[1]
(Losses) gains on foreign currency contracts, net		0.0			0.0
Loss on extinguishments of debt		0.0			0.0
Interest expense		(10.3)	(9.3)	[1]	(20.3)	(18.8)	[1]
Income before income taxes		106.1	105.2	[1]	178.3	144.0	[1]
Noncontrolling interests’ net income (loss)		0.0	0.0	[1]	0.0	0.0	[1]
Depreciation and amortization		17.7	17.0	[1]	35.1	33.7	[1]
Capital expenditures (including the effects of accruals)		56.5	48.1	[1]	120.6	109.6	[1]
Total assets		2,909.7	2,639.5	[1]	2,909.7	2,639.5	[1]
Short-term borrowings		48.5	155.0	[1]	48.5	155.0	[1]
Goodwill		182.1	182.1	[1]	182.1	182.1	[1]
Corporate & Other
Segment Reporting Information
Revenues	[4]	1.6	1.6	[1]	2.1	3.7	[1]
Cost of sales	[4]	22.9	(63.7)	[1]	(82.0)	(63.8)	[1]
Segment profit:
Operating income	[4]	(33.6)	61.2	[1]	69.8	60.7	[1]
Income (loss) from equity investees	[4]	0.0			0.0	0.0	[1]
(Losses) gains on foreign currency contracts, net	[4]	(1.3)			(0.1)
Loss on extinguishments of debt	[4]	0.0			0.0
Interest expense	[4]	0.0	(0.2)	[1]	0.0	(0.3)	[1]
Income before income taxes	[4]	(34.9)	61.0	[1]	69.7	60.4	[1]
Noncontrolling interests’ net income (loss)	[4]	(20.9)	28.7	[1]	(2.1)	24.6	[1]
Depreciation and amortization	[4]	0.3	0.4	[1]	0.5	0.5	[1]
Capital expenditures (including the effects of accruals)	[4]	0.2	0.0	[1]	0.3	0.0	[1]
Total assets	[4]	290.9	125.8	[1]	290.9	125.8	[1]
Short-term borrowings	[4]	0.0	0.0	[1]	0.0	0.0	[1]
Goodwill	[4]	0.0	0.0	[1]	0.0	0.0	[1]
Gains (losses) on unsettled commodity derivative instruments, net		(23.9)	$ 64.0		81.6	$ 65.1
Corporate & Other | Private Equity Partnership That Invests in Renewable Energy Companies
Segment profit:
Other-than-temporary impairment of investment		$ 7.0			$ 7.0

[1] Restated to reflect (1) the current-year changes in the presentation of our UGI International and Midstream & Marketing reportable segments and (2) the adoption of new accounting guidance related to debt issuance costs (see Note 2).

[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 income before income taxes: Three Months EndedMarch 31, Six Months EndedMarch 31, 2017 2016 2017 2016Partnership Adjusted EBITDA $271.2 $295.4 $456.3 $473.1Depreciation and amortization (45.0) (47.4) (89.6) (96.6)Interest expense (40.0) (40.8) (80.0) (81.8)Loss on extinguishments of debt (22.1) — (55.3) —Noncontrolling interest (i) 1.1 2.4 2.5 3.5Income before income taxes $165.2 $209.6 $233.9 $298.2(i)Principally represents the General Partner’s 1.01% interest in AmeriGas OLP.

[4] Corporate & Other results principally comprise (1) net expenses of UGI’s captive general liability insurance company and UGI’s corporate headquarters facility, and (2) UGI’s unallocated corporate and general expenses and interest income. Corporate & Other results also include the effects of net pre-tax (losses) gains on commodity and certain foreign currency derivative instruments not associated with current-period transactions (including such amounts attributable to noncontrolling interests) totaling $(23.9) and $64.0 during the three months ended March 31, 2017 and 2016, respectively, and $81.6 and $65.1 during the six months ended March 31, 2017 and 2016, respectively. Corporate & Other results for the three and six months ended March 31, 2017, also include a pre-tax loss of $7.0 associated with the impairment of a cost basis investment (see Note 2). Corporate & Other assets principally comprise cash and cash equivalents of UGI and its captive insurance company; UGI corporate headquarters’ assets; and our investment in a private equity partnership.