Utility Regulatory Assets and Liabilities and Regulatory Matters - Schedule of Regulatory Assets and Liabilities (Details) - Utilities - USD ($) $ in Millions	Dec. 31, 2025	Sep. 30, 2025	Dec. 31, 2024
Regulatory Assets
Regulatory assets	$ 321	$ 340	$ 313
Regulatory Liabilities
Regulatory liabilities	317	314	322
Postretirement benefits
Regulatory Liabilities
Regulatory liabilities	14	14	13
Deferred fuel and power refunds
Regulatory Liabilities
Regulatory liabilities	8	4	12
State income tax benefits — distribution system repairs
Regulatory Liabilities
Regulatory liabilities	49	49	45
Excess federal deferred income taxes
Regulatory Liabilities
Regulatory liabilities	238	239	245
Other
Regulatory Liabilities
Regulatory liabilities	8	8	7
Income taxes recoverable
Regulatory Assets
Regulatory assets	115	113	107
Underfunded pension plans
Regulatory Assets
Regulatory assets	99	100	105
Environmental costs
Regulatory Assets
Regulatory assets	21	22	26
Deferred fuel and power costs
Regulatory Assets
Regulatory assets	24	39	0
Removal costs, net
Regulatory Assets
Regulatory assets	31	30	30
Other
Regulatory Assets
Regulatory assets	$ 31	$ 36	$ 45

UGI CORP /PA/ 10-Q