Revenue from Contracts with Customers - Schedule of Disaggregated Revenues By Reportable Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	$ 9,981	$ 7,348	$ 6,452
Other revenues	125	99	107
Total revenues	10,106	7,447	6,559
Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	875	568	563
Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	365	218	215
Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	171	148	142
Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	76	51	48
Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	23	21	14
Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,510	1,006	982
Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	4,436	3,957	3,499
Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	496	328	211
Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	2,951	1,564	1,233
Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	211	181	168
Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	48	16	6
Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	9	8	7
Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	34	13	34
Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	286	275	312
Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	8,471	6,342	5,470
Eliminations
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(474)	(288)	(229)
Other revenues	(3)	(3)	(3)
Total revenues	(477)	(291)	(232)
Eliminations | Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Eliminations | Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Eliminations | Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Eliminations | Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(104)	(62)	(45)
Eliminations | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(1)	(2)	(2)
Eliminations | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(105)	(64)	(47)
Eliminations | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Eliminations | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Eliminations | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(264)	(126)	(79)
Eliminations | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Eliminations | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(105)	(98)	(100)
Eliminations | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Eliminations | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Eliminations | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	(3)
Eliminations | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(369)	(224)	(182)
Eliminations | AmeriGas Propane
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Eliminations | UGI International
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0
Eliminations | Midstream & Marketing
Disaggregation of Revenue [Line Items]
Total revenues	369	224	182
Eliminations | Utilities
Disaggregation of Revenue [Line Items]
Total revenues	105	64	47
Operating Segments | AmeriGas Propane
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	2,864	2,548	2,315
Other revenues	79	66	66
Total revenues	2,943	2,614	2,381
Operating Segments | AmeriGas Propane | Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | AmeriGas Propane | Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | AmeriGas Propane | Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | AmeriGas Propane | Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | AmeriGas Propane | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | AmeriGas Propane | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | AmeriGas Propane | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	2,439	2,203	2,037
Operating Segments | AmeriGas Propane | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	218	139	63
Operating Segments | AmeriGas Propane | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | AmeriGas Propane | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | AmeriGas Propane | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | AmeriGas Propane | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | AmeriGas Propane | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | AmeriGas Propane | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	207	206	215
Operating Segments | AmeriGas Propane | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	2,864	2,548	2,315
Operating Segments | UGI International
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	3,652	2,617	2,104
Other revenues	34	34	23
Total revenues	3,686	2,651	2,127
Operating Segments | UGI International | Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | UGI International | Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | UGI International | Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | UGI International | Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | UGI International | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | UGI International | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | UGI International | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,997	1,754	1,462
Operating Segments | UGI International | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	278	189	148
Operating Segments | UGI International | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,298	605	434
Operating Segments | UGI International | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | UGI International | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | UGI International | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | UGI International | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | UGI International | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	79	69	60
Operating Segments | UGI International | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	3,652	2,617	2,104
Operating Segments | Midstream & Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	2,324	1,401	1,233
Other revenues	2	5	14
Total revenues	2,326	1,406	1,247
Operating Segments | Midstream & Marketing | Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Midstream & Marketing | Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Midstream & Marketing | Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Midstream & Marketing | Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Midstream & Marketing | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Midstream & Marketing | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Midstream & Marketing | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Midstream & Marketing | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Midstream & Marketing | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,917	1,085	878
Operating Segments | Midstream & Marketing | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	211	181	168
Operating Segments | Midstream & Marketing | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	153	114	106
Operating Segments | Midstream & Marketing | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	9	8	7
Operating Segments | Midstream & Marketing | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	34	13	34
Operating Segments | Midstream & Marketing | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	40
Operating Segments | Midstream & Marketing | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	2,324	1,401	1,233
Operating Segments | Utilities
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,615	1,070	1,029
Other revenues	5	9	1
Total revenues	1,620	1,079	1,030
Operating Segments | Utilities | Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	875	568	563
Operating Segments | Utilities | Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	365	218	215
Operating Segments | Utilities | Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	171	148	142
Operating Segments | Utilities | Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	180	113	93
Operating Segments | Utilities | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	24	23	16
Operating Segments | Utilities | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,615	1,070	1,029
Operating Segments | Utilities | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Utilities | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Utilities | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Utilities | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Utilities | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Utilities | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Utilities | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Utilities | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Operating Segments | Utilities | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Other revenues	8	(12)	6
Total revenues	8	(12)	6
Corporate & Other | Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other | Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other | Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other | Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0	0
Corporate & Other | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	$ 0	$ 0	$ 0