Segment Information - Schedule of Segment Reporting (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Revenues	$ 10,106	$ 7,447	$ 6,559
Cost of sales	5,973	2,614	3,149
Operating income	1,666	2,350	982
(Loss) income from equity investees	(14)	(63)	27
Loss on extinguishment of debt	(11)	0	0
Other non-operating income, net	75	12	(20)
Earnings (loss) before interest expense and income taxes	1,716	2,299	989
Interest expense	(329)	(310)	(322)
Income tax expense	(313)	(522)	(135)
Noncontrolling interests’ net (income) loss	(1)	0	0
Net income attributable to UGI Corporation	1,073	1,467	532
Depreciation and amortization	518	502	484
Total assets	17,575	16,723	13,985
Short-term borrowings	368	367	347
Capital expenditures (including the effects of accruals)	835	674	665
Investments in equity investees	130	174	200
Eliminations
Segment Reporting Information [Line Items]
Revenues	(477)	(291)	(232)
Cost of sales	(474)	(288)	(229)
Operating income	0	0	0
(Loss) income from equity investees	0	0	0
Loss on extinguishment of debt	0
Other non-operating income, net	0	0	0
Earnings (loss) before interest expense and income taxes	0	0	0
Interest expense	0	0	0
Income tax expense	0	0	0
Noncontrolling interests’ net (income) loss	0
Net income attributable to UGI Corporation	0	0	0
Depreciation and amortization	0	0	0
Total assets	(203)	(241)	(282)
Short-term borrowings	0	0	0
Capital expenditures (including the effects of accruals)	0	0	0
Investments in equity investees	0	0	0
Eliminations | AmeriGas Propane
Segment Reporting Information [Line Items]
Revenues	0	0	0
Eliminations | UGI International
Segment Reporting Information [Line Items]
Revenues	0	0	0
Eliminations | Midstream & Marketing
Segment Reporting Information [Line Items]
Revenues	369	224	182
Eliminations | Utilities
Segment Reporting Information [Line Items]
Revenues	105	64	47
Operating Segments | AmeriGas Propane
Segment Reporting Information [Line Items]
Revenues	2,943	2,614	2,381
Cost of sales	1,613	1,217	960
Operating income	307	385	373
(Loss) income from equity investees	0	0	0
Loss on extinguishment of debt	0
Other non-operating income, net	0	0	0
Earnings (loss) before interest expense and income taxes	307	385	373
Interest expense	(160)	(159)	(164)
Income tax expense	(35)	(58)	(53)
Noncontrolling interests’ net (income) loss	0
Net income attributable to UGI Corporation	112	168	156
Depreciation and amortization	177	173	178
Total assets	4,332	4,485	4,327
Short-term borrowings	131	170	186
Capital expenditures (including the effects of accruals)	128	130	135
Investments in equity investees	0	0	0
Operating Segments | UGI International
Segment Reporting Information [Line Items]
Revenues	3,686	2,651	2,127
Cost of sales	2,751	1,598	1,191
Operating income	237	314	241
(Loss) income from equity investees	(2)	0	0
Loss on extinguishment of debt	0
Other non-operating income, net	19	3	18
Earnings (loss) before interest expense and income taxes	254	317	259
Interest expense	(28)	(27)	(31)
Income tax expense	(50)	(69)	(55)
Noncontrolling interests’ net (income) loss	(1)
Net income attributable to UGI Corporation	175	221	173
Depreciation and amortization	116	134	125
Total assets	4,610	4,421	3,123
Short-term borrowings	1	0	1
Capital expenditures (including the effects of accruals)	107	107	89
Investments in equity investees	20	11	10
Operating Segments | Midstream & Marketing
Segment Reporting Information [Line Items]
Revenues	2,326	1,406	1,247
Revenues from external customers	1,957	1,182	1,065
Cost of sales	1,876	1,033	892
Operating income	246	160	140
(Loss) income from equity investees	23	30	27
Loss on extinguishment of debt	0
Other non-operating income, net	0	0	1
Earnings (loss) before interest expense and income taxes	269	190	168
Interest expense	(41)	(42)	(42)
Income tax expense	(65)	(41)	(34)
Noncontrolling interests’ net (income) loss	0
Net income attributable to UGI Corporation	163	107	92
Depreciation and amortization	79	76	75
Total assets	3,286	3,010	2,775
Short-term borrowings	0	0	19
Capital expenditures (including the effects of accruals)	38	43	93
Investments in equity investees	109	163	190
Operating Segments | Utilities
Segment Reporting Information [Line Items]
Revenues	1,620	1,079	1,030
Revenues from external customers	1,515	1,015	983
Cost of sales	798	458	448
Operating income	327	241	229
(Loss) income from equity investees	0	0	0
Loss on extinguishment of debt	0
Other non-operating income, net	9	1	0
Earnings (loss) before interest expense and income taxes	336	242	229
Interest expense	(65)	(56)	(54)
Income tax expense	(65)	(42)	(39)
Noncontrolling interests’ net (income) loss	0
Net income attributable to UGI Corporation	206	144	136
Depreciation and amortization	144	119	105
Total assets	5,354	4,859	3,809
Short-term borrowings	236	197	141
Capital expenditures (including the effects of accruals)	562	394	348
Investments in equity investees	0	0	0
Corporate & Other
Segment Reporting Information [Line Items]
Revenues	8	(12)	6
Revenues from external customers	5	(15)	3
Cost of sales	(591)	(1,404)	(113)
Operating income	549	1,250	(1)
(Loss) income from equity investees	(35)	(93)	0
Loss on extinguishment of debt	(11)
Other non-operating income, net	47	8	(39)
Earnings (loss) before interest expense and income taxes	550	1,165	(40)
Interest expense	(35)	(26)	(31)
Income tax expense	(98)	(312)	46
Noncontrolling interests’ net (income) loss	0
Net income attributable to UGI Corporation	417	827	(25)
Depreciation and amortization	2	0	1
Total assets	196	189	233
Short-term borrowings	0	0	0
Capital expenditures (including the effects of accruals)	0	0	0
Investments in equity investees	1	0	0
Corporate & Other | AmeriGas Propane
Segment Reporting Information [Line Items]
Loss on extinguishment of debt	0
Corporate & Other | UGI International
Segment Reporting Information [Line Items]
Loss on extinguishment of debt	(11)
Corporate & Other | Midstream & Marketing
Segment Reporting Information [Line Items]
Loss on extinguishment of debt	0
Corporate, Intersegment Eliminations & Other
Segment Reporting Information [Line Items]
Revenues	$ 3	$ 3	$ 3