Revenue from Contracts with Customers - Disaggregated Revenues by Reportable Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	$ 2,074	$ 2,721
Other revenues	47	38
Total revenues	2,121	2,759
Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	469	557
Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	282	336
Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	108	132
Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	49	47
Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	21	32
Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	9	10
Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,605	2,164
Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,057	1,116
Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	71	102
Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	327	778
Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	65	65
Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	3	17
Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	3	3
Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	8	8
Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	71	75
Eliminations
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(80)	(149)
Other revenues	0	0
Total revenues	(80)	(149)
Eliminations | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(12)	(33)
Eliminations | Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Eliminations | Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Eliminations | Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Eliminations | Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(12)	(33)
Eliminations | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Eliminations | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(68)	(116)
Eliminations | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Eliminations | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Eliminations | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(26)	(77)
Eliminations | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Eliminations | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(42)	(39)
Eliminations | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Eliminations | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Eliminations | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Eliminations | Utilities
Disaggregation of Revenue [Line Items]
Total revenues	13	33
Eliminations | Midstream & Marketing
Disaggregation of Revenue [Line Items]
Total revenues	67	115
Eliminations | UGI International
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Eliminations | AmeriGas Propane
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Utilities
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	481	590
Other revenues	12	2
Total revenues	493	592
Operating Segments | Utilities | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	481	590
Operating Segments | Utilities | Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	282	336
Operating Segments | Utilities | Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	108	132
Operating Segments | Utilities | Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	49	47
Operating Segments | Utilities | Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	33	65
Operating Segments | Utilities | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	9	10
Operating Segments | Utilities | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Utilities | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Utilities | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Utilities | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Utilities | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Utilities | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Utilities | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Utilities | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Utilities | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Midstream & Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	393	669
Other revenues	1	0
Total revenues	394	669
Operating Segments | Midstream & Marketing | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Midstream & Marketing | Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Midstream & Marketing | Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Midstream & Marketing | Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	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
Operating Segments | Midstream & Marketing | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Midstream & Marketing | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	393	669
Operating Segments | Midstream & Marketing | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Midstream & Marketing | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Midstream & Marketing | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	272	537
Operating Segments | Midstream & Marketing | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	65	65
Operating Segments | Midstream & Marketing | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	45	56
Operating Segments | Midstream & Marketing | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	3	3
Operating Segments | Midstream & Marketing | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	8	8
Operating Segments | Midstream & Marketing | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI International
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	715	869
Other revenues	10	8
Total revenues	725	877
Operating Segments | UGI International | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI International | Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI International | Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI International | Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	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
Operating Segments | UGI International | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI International | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	715	869
Operating Segments | UGI International | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	524	482
Operating Segments | UGI International | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	49	51
Operating Segments | UGI International | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	123	318
Operating Segments | UGI International | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI International | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI International | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI International | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI International | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	19	18
Operating Segments | AmeriGas Propane
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	607	742
Other revenues	22	24
Total revenues	629	766
Operating Segments | AmeriGas Propane | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | AmeriGas Propane | Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | AmeriGas Propane | Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | AmeriGas Propane | Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	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
Operating Segments | AmeriGas Propane | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | AmeriGas Propane | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	607	742
Operating Segments | AmeriGas Propane | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	533	634
Operating Segments | AmeriGas Propane | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	22	51
Operating Segments | AmeriGas Propane | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | AmeriGas Propane | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | AmeriGas Propane | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | AmeriGas Propane | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | AmeriGas Propane | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | AmeriGas Propane | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	52	57
Corporate & Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(42)	0
Other revenues	2	4
Total revenues	(40)	4
Corporate & Other | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Corporate & Other | Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Corporate & Other | Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Corporate & Other | Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Corporate & Other | Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Corporate & Other | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Corporate & Other | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(42)	0
Corporate & Other | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Corporate & Other | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Corporate & Other | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(42)	0
Reduction in revenue	42
Corporate & Other | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Corporate & Other | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Corporate & Other | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Corporate & Other | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Corporate & Other | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	$ 0	$ 0