Benefit Plans and Other Postretirement Benefits, Postretirement Health Care Benefits (Details) $ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Postretirement Health Care Benefits [Abstract]
Estimated costs of health plan subsidies - VRP	$ 29	$ 34
Estimated cost of other medical benefits - VRP	$ 4	$ 5
Defined Benefit Plan, Health Care Cost Trend Rate Assumed and Ultimate Trend Assumption, Ultimate Trend Assumption	0.0450
Years until ultimate trend is reached	9 years
Other Postretirement Benefits Plan [Member]
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	100.00%	100.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate, VRP	0.0500	0.0550
Defined Benefit Plan, Health Care Cost Trend Rate Assumed and Ultimate Trend Assumption, VRP	0.0700	0.0700
Pension Plan [Member]
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	100.00%	100.00%
Equity Securities | Other Postretirement Benefits Plan [Member]
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	25.00%	9.00%
Equity Securities | Pension Plan [Member]
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	31.00%	31.00%
Long-duration fixed income and interest rate swap securities | Other Postretirement Benefits Plan [Member]
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	0.00%	0.00%
Long-duration fixed income and interest rate swap securities | Pension Plan [Member]
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	38.00%	38.00%
Short-to-intermediate fixed income securities | Other Postretirement Benefits Plan [Member]
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	61.00%	77.00%
Short-to-intermediate fixed income securities | Pension Plan [Member]
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	9.00%	9.00%
Alternative investments | Other Postretirement Benefits Plan [Member]
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	11.00%	13.00%
Alternative investments | Pension Plan [Member]
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	20.00%	20.00%
Cash | Other Postretirement Benefits Plan [Member]
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	3.00%	1.00%
Cash | Pension Plan [Member]
Postretirement Health Care Benefits [Abstract]
Target pension asset allocations (as a percent)	2.00%	2.00%