Revenue from Contracts with Customers - Disaggregated Revenues by Reportable Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	$ 2,721	$ 2,636
Other revenues	38	37
Total revenues	2,759	2,673
Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	557	395
Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	336	234
Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	132	94
Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	47	43
Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	32	19
Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	10	5
Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	2,164	2,241
Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,116	1,250
Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	102	140
Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	778	714
Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	65	46
Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	17	6
Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	3	2
Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	8	5
Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	75	78
Eliminations
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(149)	(117)
Other revenues	0	(1)
Total revenues	(149)	(118)
Eliminations | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(33)	(23)
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	(33)	(22)
Eliminations | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	(1)
Eliminations | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(116)	(94)
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	(77)	(55)
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	(39)	(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 | AmeriGas Propane
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Eliminations | UGI International
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Eliminations | Midstream & Marketing
Disaggregation of Revenue [Line Items]
Total revenues	115	94
Eliminations | Utilities
Disaggregation of Revenue [Line Items]
Total revenues	33	23
Operating Segments | AmeriGas Propane
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	742	760
Other revenues	24	18
Total revenues	766	778
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	742	760
Operating Segments | AmeriGas Propane | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	634	646
Operating Segments | AmeriGas Propane | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	51	56
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	57	58
Operating Segments | UGI International
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	869	1,041
Other revenues	8	8
Total revenues	877	1,049
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	869	1,041
Operating Segments | UGI International | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	482	604
Operating Segments | UGI International | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	51	84
Operating Segments | UGI International | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	318	333
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	18	20
Operating Segments | Midstream & Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	669	534
Other revenues	0	1
Total revenues	669	535
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	669	534
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	537	436
Operating Segments | Midstream & Marketing | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	65	46
Operating Segments | Midstream & Marketing | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	56	45
Operating Segments | Midstream & Marketing | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	3	2
Operating Segments | Midstream & Marketing | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	8	5
Operating Segments | Midstream & Marketing | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | Utilities
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	590	418
Other revenues	2	1
Total revenues	592	419
Operating Segments | Utilities | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	590	418
Operating Segments | Utilities | Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	336	234
Operating Segments | Utilities | Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	132	94
Operating Segments | Utilities | Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	47	43
Operating Segments | Utilities | Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	65	41
Operating Segments | Utilities | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	10	6
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
Corporate & Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Other revenues	4	10
Total revenues	4	10
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	0	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	0	0
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