Pension And Postretirement Benefits (Other Changes Recognized in Other Comprehensive Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax [Roll Forward]
Prior service (cost) credit	$ 0	$ 32	$ 1,787
Amortization of prior service credit	(1,523)	(1,963)	(2,028)
Pension Benefits
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax [Roll Forward]
Balance at beginning of year	216	316	416
Prior service (cost) credit	0	0	0
Amortization of prior service credit	(66)	(100)	(100)
Total recognized in other comprehensive (income) loss	(66)	(100)	(100)
Balance at end of year	150	216	316
Postretirement Benefits
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax [Roll Forward]
Balance at beginning of year	4,523	6,354	6,496
Prior service (cost) credit	0	32	1,786
Amortization of prior service credit	(1,457)	(1,863)	(1,928)
Total recognized in other comprehensive (income) loss	(1,457)	(1,831)	(142)
Balance at end of year	$ 3,066	$ 4,523	$ 6,354