Retirement Benefits (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024
DB Pension Plans \| Volatility Mechanism
Defined Benefit Plan Disclosure [Line Items]
Deferred credits	$ 1	$ 9
OPEB Plan \| Volatility Mechanism
Defined Benefit Plan Disclosure [Line Items]
Deferred credits	$ 5
OPEB Plan \| Volatility Mechanism
Defined Benefit Plan Disclosure [Line Items]
Deferred credits		$ 4

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details