Retirement Benefits and Trusteed Assets (Pension Plan - Pension Cost Inclusions) (Details) - Pension plan - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 58	$ 57	$ 95
Interest cost	208	214	166
Expected return on plan assets	(341)	(352)	(346)
Amortization of:
Net actuarial loss	59	7	115
Prior service credit	(2)	(2)	(1)
Settlements	0	7	94
Net pension/other postretirement cost (credit)	$ (18)	$ (69)	$ 123