Accumulated Other Comprehensive (Loss) Income (Changes Net of Tax In The Balances of Each Components of Other Accumulated Comprehensive Income Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of year	$ 10,749	$ 11,222
Other comprehensive (loss) income before reclassifications	5	(849)
Amounts reclassified from accumulated other comprehensive income	14	110
Other comprehensive income (loss), net of tax	19	(739)	$ 535
Balance, end of year	12,370	10,749	11,222
Total
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of year	(5,314)	(4,575)	(5,110)
Other comprehensive income (loss), net of tax	19	(739)	535
Balance, end of year	(5,295)	(5,314)	(4,575)
Pension/Post-Retirement Plans Gains (Losses)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of year	(2,721)	(3,202)
Other comprehensive (loss) income before reclassifications	(394)	371
Amounts reclassified from accumulated other comprehensive income	14	110
Other comprehensive income (loss), net of tax	(380)	481	924
Balance, end of year	(3,101)	(2,721)	(3,202)
Foreign currency translation adjustments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, beginning of year	(2,593)	(1,373)
Other comprehensive (loss) income before reclassifications	399	(1,220)	(389)
Amounts reclassified from accumulated other comprehensive income	0	0
Other comprehensive income (loss), net of tax	399	(1,220)
Balance, end of year	$ (2,194)	$ (2,593)	$ (1,373)