Segment Information - Schedule of Segment Reporting Information (Details) - USD ($) $ in Millions		3 Months Ended
		Dec. 31, 2016	Dec. 31, 2015		Sep. 30, 2016
Segment Reporting Information
Revenues		$ 1,679.5	$ 1,606.6	[1]
Cost of sales		647.4	734.0	[1]
Segment profit:
Operating income (loss)		466.2	305.5	[1]
Loss from equity investees		(0.2)	(0.1)	[1]
Gains on foreign currency contracts, net		1.3	0.0
Loss on extinguishment of debt		(33.2)	0.0
Interest expense		(55.4)	(57.9)	[1]
Income before income taxes		378.7	247.5	[1]
Noncontrolling interests’ net income (loss)		60.2	53.3	[1]
Depreciation and amortization		98.1	100.6	[1]
Capital expenditures (including the effects of accruals)		173.6	132.9	[1]
Total assets		11,300.5	10,749.7	[1]	$ 10,847.2
Short-term borrowings		234.4	456.8	[1]	291.7
Goodwill		2,935.8	2,965.1	[1]	$ 2,989.0
Eliminations
Segment Reporting Information
Revenues	[2]	(68.5)	(42.7)	[1]
Cost of sales	[2]	(67.7)	(41.8)	[1]
Segment profit:
Operating income (loss)		0.1	0.1	[1]
Loss from equity investees		0.0	0.0	[1]
Gains on foreign currency contracts, net		0.0
Loss on extinguishment of debt		0.0
Interest expense		0.0	0.0	[1]
Income before income taxes		0.1	0.1	[1]
Noncontrolling interests’ net income (loss)		0.0	0.0	[1]
Depreciation and amortization		0.0	0.0	[1]
Capital expenditures (including the effects of accruals)		0.0	0.0	[1]
Total assets		(107.9)	(106.2)	[1]
Short-term borrowings		0.0	0.0	[1]
Goodwill		0.0	0.0	[1]
Operating Segments | AmeriGas Propane
Segment Reporting Information
Revenues		677.2	644.1	[1]
Cost of sales		260.7	243.2	[1]
Segment profit:
Operating income (loss)		141.9	129.6	[1]
Loss from equity investees		0.0	0.0	[1]
Gains on foreign currency contracts, net		0.0
Loss on extinguishment of debt		(33.2)	0.0
Interest expense		(40.0)	(41.0)	[1]
Income before income taxes		68.7	88.6	[1]
Partnership Adjusted EBITDA	[3]	185.1	177.7	[1]
Noncontrolling interests’ net income (loss)		41.2	57.3	[1]
Depreciation and amortization		44.6	49.2	[1]
Capital expenditures (including the effects of accruals)		26.4	28.0	[1]
Total assets		4,217.9	4,222.1	[1]
Short-term borrowings		77.5	182.0	[1]
Goodwill		1,978.5	1,971.3	[1]
Operating Segments | UGI International
Segment Reporting Information
Revenues		539.1	578.2	[1]
Cost of sales		258.0	302.8	[1]
Segment profit:
Operating income (loss)		88.9	85.1	[1]
Loss from equity investees		(0.2)	(0.1)	[1]
Gains on foreign currency contracts, net		0.1
Loss on extinguishment of debt		0.0
Interest expense		(4.8)	(6.5)	[1]
Income before income taxes		84.0	78.5	[1]
Noncontrolling interests’ net income (loss)		0.2	0.1	[1]
Depreciation and amortization		27.9	27.2	[1]
Capital expenditures (including the effects of accruals)		21.5	21.0	[1]
Total assets		2,853.4	2,905.8	[1]
Short-term borrowings		3.5	1.1	[1]
Goodwill		763.7	800.2	[1]
Operating Segments | Midstream & Marketing
Segment Reporting Information
Revenues		269.8	226.9	[1]
Cost of sales		191.8	154.5	[1]
Segment profit:
Operating income (loss)		49.7	42.9	[1]
Loss from equity investees		0.0	0.0	[1]
Gains on foreign currency contracts, net		0.0
Loss on extinguishment of debt		0.0
Interest expense		(0.6)	(0.8)	[1]
Income before income taxes		49.1	42.1	[1]
Noncontrolling interests’ net income (loss)		0.0	0.0	[1]
Depreciation and amortization		8.0	7.4	[1]
Capital expenditures (including the effects of accruals)		61.5	22.4	[1]
Total assets		1,178.4	1,000.0	[1]
Short-term borrowings		55.0	56.0	[1]
Goodwill		11.5	11.5	[1]
Operating Segments | UGI Utilities
Segment Reporting Information
Revenues		261.4	198.0	[1]
Cost of sales		109.5	75.4	[1]
Segment profit:
Operating income (loss)		82.2	48.3	[1]
Loss from equity investees		0.0	0.0	[1]
Gains on foreign currency contracts, net		0.0
Loss on extinguishment of debt		0.0
Interest expense		(10.0)	(9.5)	[1]
Income before income taxes		72.2	38.8	[1]
Noncontrolling interests’ net income (loss)		0.0	0.0	[1]
Depreciation and amortization		17.4	16.7	[1]
Capital expenditures (including the effects of accruals)		64.1	61.5	[1]
Total assets		2,898.5	2,604.2	[1]
Short-term borrowings		98.4	217.7	[1]
Goodwill		182.1	182.1	[1]
Corporate & Other
Segment Reporting Information
Revenues	[4]	0.5	2.1	[1]
Cost of sales	[4]	(104.9)	(0.1)	[1]
Segment profit:
Operating income (loss)	[4]	103.4	(0.5)	[1]
Loss from equity investees	[4]	0.0	0.0	[1]
Gains on foreign currency contracts, net		1.2
Loss on extinguishment of debt	[4]	0.0
Interest expense	[4]	0.0	(0.1)	[1]
Income before income taxes	[4]	104.6	(0.6)	[1]
Noncontrolling interests’ net income (loss)	[4]	18.8	(4.1)	[1]
Depreciation and amortization	[4]	0.2	0.1	[1]
Capital expenditures (including the effects of accruals)	[4]	0.1	0.0	[1]
Total assets	[4]	260.2	123.8	[1]
Short-term borrowings	[4]	0.0	0.0	[1]
Goodwill	[4]	0.0	0.0	[1]
Gains (losses) on unsettled commodity derivative instruments, net		$ 105.5	$ 1.1

[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 EndedDecember 31, 2016 2015Partnership Adjusted EBITDA $185.1 $177.7Depreciation and amortization (44.6) (49.2)Interest expense (40.0) (41.0)Loss on extinguishment of debt (33.2) —Noncontrolling interest (i) 1.4 1.1Income before income taxes $68.7 $88.6(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. In addition, Corporate & Other results also include the effects of net pre-tax gains on commodity and certain foreign currency derivative instruments not associated with current-period transactions (including such amounts attributable to noncontrolling interests) totaling $105.5 and $1.1 during the three months ended December 31, 2016 and 2015, respectively. 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.