v3.26.1
Segment Information - Schedule of Reconciliation of Partnership Adjusted EBITDA (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Segment Reporting [Line Items]        
Net gains (losses) on commodity derivative instruments     $ 55 $ (30)
Loss on extinguishments of debt $ (15) $ (10) (15) (10)
Net gain (loss) on disposals of businesses (7) (54) (42) (54)
Midstream & Marketing        
Segment Reporting [Line Items]        
Loss on extinguishments of debt (2) 0 (2) 0
Net gain (loss) on disposals of businesses 0 0 0 0
Restructuring costs 0   0  
Interest income from intersegment loan 0 0 0 0
Midstream & Marketing | Income Statement Location [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization        
Segment Reporting [Line Items]        
Net gains (losses) on commodity derivative instruments 0 (59) (28) 26
Midstream & Marketing | Income Statement Location [Axis]: us-gaap:OtherNonoperatingIncomeExpense        
Segment Reporting [Line Items]        
Net gains (losses) on commodity derivative instruments 0 0 0 0
Midstream & Marketing | Income Statement Location [Axis]: us-gaap:OtherOperatingIncomeExpenseNet        
Segment Reporting [Line Items]        
Net gains (losses) on commodity derivative instruments 0 0 0  
Midstream & Marketing | Income Statement Location [Axis]: us-gaap:Revenues        
Segment Reporting [Line Items]        
Net gains (losses) on commodity derivative instruments   1   (1)
UGI International        
Segment Reporting [Line Items]        
Loss on extinguishments of debt 0 0 0 0
Net gain (loss) on disposals of businesses (7) (54) (42) (54)
Restructuring costs 0   0  
Interest income from intersegment loan 2 5 10 8
UGI International | Income Statement Location [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization        
Segment Reporting [Line Items]        
Net gains (losses) on commodity derivative instruments (76) (50) 54 (46)
UGI International | Income Statement Location [Axis]: us-gaap:OtherNonoperatingIncomeExpense        
Segment Reporting [Line Items]        
Net gains (losses) on commodity derivative instruments 7 (25) 23 (16)
UGI International | Income Statement Location [Axis]: us-gaap:OtherOperatingIncomeExpenseNet        
Segment Reporting [Line Items]        
Net gains (losses) on commodity derivative instruments (2) (1) 2  
UGI International | Income Statement Location [Axis]: us-gaap:Revenues        
Segment Reporting [Line Items]        
Net gains (losses) on commodity derivative instruments   0   0
AmeriGas Propane        
Segment Reporting [Line Items]        
Loss on extinguishments of debt (13) (9) (13) (9)
Net gain (loss) on disposals of businesses 0 0 0 0
Restructuring costs (2)   (2)  
Interest income from intersegment loan 0 0 0 0
AmeriGas Propane | Income Statement Location [Axis]: us-gaap:CostOfGoodsAndServiceExcludingDepreciationDepletionAndAmortization        
Segment Reporting [Line Items]        
Net gains (losses) on commodity derivative instruments (13) (3) 4 7
AmeriGas Propane | Income Statement Location [Axis]: us-gaap:OtherNonoperatingIncomeExpense        
Segment Reporting [Line Items]        
Net gains (losses) on commodity derivative instruments 0 0 0 0
AmeriGas Propane | Income Statement Location [Axis]: us-gaap:OtherOperatingIncomeExpenseNet        
Segment Reporting [Line Items]        
Net gains (losses) on commodity derivative instruments $ 0 0 $ 0  
AmeriGas Propane | Income Statement Location [Axis]: us-gaap:Revenues        
Segment Reporting [Line Items]        
Net gains (losses) on commodity derivative instruments   $ 0   $ 0