Retirement Plans (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Capitalization of pension and OPEB expense	$ 4	$ 4
Pension remeasurement gain	44	74
OPEB remeasurement gain	(8)	9
Pension [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions to plans	29
Pension remeasurement gain	44	74
Increase in plan assets	42
Plan assets	2,370		$ 2,328
Investment returns	53
Benefit payments	40
Special termination benefits		6
OPEB [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
OPEB remeasurement gain	$ (8)	9
Special termination benefits		$ 1