Retirement Benefits Unamortized Prior Service Credit Rollforward (Details 2) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Amortization of:
Prior service credit	$ 0	$ 1	$ 1
Tax expense (benefit) related to above items	3	0	0
Change in unamortized benefit plan costs	(9)	1	1
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), before Tax	(12)
Pension Benefits
Amortization of:
Prior service credit	0	0	0
Tax expense (benefit) related to above items	0	0	0
Change in unamortized benefit plan costs	0	0	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), before Tax	0
Medical and Life Benefits
Amortization of:
Prior service credit	0	1	1
Tax expense (benefit) related to above items	3	0	0
Change in unamortized benefit plan costs	(9)	$ 1	$ 1
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), before Tax	$ (12)