Segment Information - Reconciliation of Partnership Adjusted EBITDA (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Net gains on commodity derivative instruments not associated with current-period transactions			$ (1,713)	$ 341
Loss on disposal of U.K. energy marketing business	$ 0	$ 0	(215)	0
Impairment of assets			(19)	0
Loss on extinguishment of debt	0	$ 0	0	$ (11)
Restructuring, Incurred Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]		Operating and administrative expenses		Operating and administrative expenses
Corporate & Other
Segment Reporting Information [Line Items]
Loss on extinguishment of debt				$ (11)
AmeriGas Propane | Corporate & Other
Segment Reporting Information [Line Items]
Loss on extinguishment of debt				0
AmeriGas Propane | Revenues | Corporate & Other
Segment Reporting Information [Line Items]
Net gains on commodity derivative instruments not associated with current-period transactions	0	$ 0	0	0
AmeriGas Propane | Cost of sales | Corporate & Other
Segment Reporting Information [Line Items]
Net gains on commodity derivative instruments not associated with current-period transactions	8	32	(4)	(37)
AmeriGas Propane | Other operating income, net | Corporate & Other
Segment Reporting Information [Line Items]
Net gains on commodity derivative instruments not associated with current-period transactions	0		0
AmeriGas Propane | Other non-operating income (expense), net | Corporate & Other
Segment Reporting Information [Line Items]
Net gains on commodity derivative instruments not associated with current-period transactions	0	0	0	0
AmeriGas Propane | Operating and administrative expenses
Segment Reporting Information [Line Items]
AmeriGas operations enhancement for growth project	(6)
AmeriGas Propane | Operating and administrative expenses | Corporate & Other
Segment Reporting Information [Line Items]
Restructuring costs		(14)		(14)
AmeriGas operations enhancement for growth project			(13)
Impairment of assets			0
AmeriGas Propane | Loss on disposal of U.K. energy marketing business | Corporate & Other
Segment Reporting Information [Line Items]
Loss on disposal of U.K. energy marketing business			0
UGI International | Corporate & Other
Segment Reporting Information [Line Items]
Loss on extinguishment of debt				(11)
UGI International | Revenues | Corporate & Other
Segment Reporting Information [Line Items]
Net gains on commodity derivative instruments not associated with current-period transactions	1	2	3	5
UGI International | Cost of sales | Corporate & Other
Segment Reporting Information [Line Items]
Net gains on commodity derivative instruments not associated with current-period transactions	(235)	560	(1,404)	348
UGI International | Other operating income, net | Corporate & Other
Segment Reporting Information [Line Items]
Net gains on commodity derivative instruments not associated with current-period transactions	(1)		(3)
UGI International | Other non-operating income (expense), net | Corporate & Other
Segment Reporting Information [Line Items]
Net gains on commodity derivative instruments not associated with current-period transactions	(10)	(1)	(50)	5
UGI International | Operating and administrative expenses
Segment Reporting Information [Line Items]
AmeriGas operations enhancement for growth project	0
UGI International | Operating and administrative expenses | Corporate & Other
Segment Reporting Information [Line Items]
Restructuring costs		(2)		(2)
AmeriGas operations enhancement for growth project			0
Impairment of assets			(19)
UGI International | Loss on disposal of U.K. energy marketing business | Corporate & Other
Segment Reporting Information [Line Items]
Loss on disposal of U.K. energy marketing business			(215)
Midstream & Marketing | Corporate & Other
Segment Reporting Information [Line Items]
Loss on extinguishment of debt				0
Midstream & Marketing | Revenues | Corporate & Other
Segment Reporting Information [Line Items]
Net gains on commodity derivative instruments not associated with current-period transactions	4	(9)	6	(2)
Midstream & Marketing | Cost of sales | Corporate & Other
Segment Reporting Information [Line Items]
Net gains on commodity derivative instruments not associated with current-period transactions	(78)	154	(261)	22
Midstream & Marketing | Other operating income, net | Corporate & Other
Segment Reporting Information [Line Items]
Net gains on commodity derivative instruments not associated with current-period transactions	0		0
Midstream & Marketing | Other non-operating income (expense), net | Corporate & Other
Segment Reporting Information [Line Items]
Net gains on commodity derivative instruments not associated with current-period transactions	0	0	0	0
Midstream & Marketing | Operating and administrative expenses
Segment Reporting Information [Line Items]
AmeriGas operations enhancement for growth project	$ 0
Midstream & Marketing | Operating and administrative expenses | Corporate & Other
Segment Reporting Information [Line Items]
Restructuring costs		$ 0		$ 0
AmeriGas operations enhancement for growth project			0
Impairment of assets			0
Midstream & Marketing | Loss on disposal of U.K. energy marketing business | Corporate & Other
Segment Reporting Information [Line Items]
Loss on disposal of U.K. energy marketing business			$ 0