Revenue from Contracts with Customers - Disaggregated Revenues by Reportable Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	$ 2,636	$ 1,903
Other revenues	37	29
Total revenues	2,673	1,932
Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	395	284
Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	234	165
Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	94	60
Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	43	40
Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	19	15
Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	5	4
Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	2,241	1,619
Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,250	1,055
Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	140	59
Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	714	380
Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	46	45
Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	6	2
Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	2	2
Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	5	4
Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	78	72
Eliminations
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(117)	(77)
Other revenues	(1)	(1)
Total revenues	(118)	(78)
Eliminations | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(23)	(15)
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	(22)	(14)
Eliminations | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(1)	(1)
Eliminations | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	(94)	(62)
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	(55)	(26)
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)	(36)
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	94	62
Eliminations | UGI Utilities
Disaggregation of Revenue [Line Items]
Total revenues	23	15
Operating Segments | AmeriGas Propane
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	760	647
Other revenues	18	19
Total revenues	778	666
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	760	647
Operating Segments | AmeriGas Propane | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	646	572
Operating Segments | AmeriGas Propane | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	56	19
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	58	56
Operating Segments | UGI International
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	1,041	694
Other revenues	8	6
Total revenues	1,049	700
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	1,041	694
Operating Segments | UGI International | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	604	483
Operating Segments | UGI International | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	84	40
Operating Segments | UGI International | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	333	155
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	20	16
Operating Segments | Midstream & Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	534	340
Other revenues	1	1
Total revenues	535	341
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	534	340
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	436	251
Operating Segments | Midstream & Marketing | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	46	45
Operating Segments | Midstream & Marketing | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	45	38
Operating Segments | Midstream & Marketing | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	2	2
Operating Segments | Midstream & Marketing | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	5	4
Operating Segments | Midstream & Marketing | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI Utilities
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	418	299
Other revenues	1	1
Total revenues	419	300
Operating Segments | UGI Utilities | Total Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	418	299
Operating Segments | UGI Utilities | Residential
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	234	165
Operating Segments | UGI Utilities | Commercial & Industrial
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	94	60
Operating Segments | UGI Utilities | Large delivery service
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	43	40
Operating Segments | UGI Utilities | Off-system sales and capacity releases
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	41	29
Operating Segments | UGI Utilities | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	6	5
Operating Segments | UGI Utilities | Total Non-Utility
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI Utilities | Retail
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI Utilities | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI Utilities | Energy Marketing
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI Utilities | Pipeline
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI Utilities | Peaking
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI Utilities | Other
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI Utilities | Electricity Generation
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers	0	0
Operating Segments | UGI 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	10	3
Total revenues	10	3
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