Accumulated Other Comprehensive Income (Loss) (Components of Other Accumulated Comprehensive Income Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 11,222	$ 9,260
Other comprehensive income (loss) before reclassifications	(849)	376
Amounts reclassified from accumulated other comprehensive loss	110	159
Other comprehensive (loss) income, net of tax	(739)	535	$ (55)
Ending balance	10,749	11,222	9,260
Total
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(4,575)	(5,110)	(5,055)
Other comprehensive (loss) income, net of tax	(739)	535	(55)
Ending balance	(5,314)	(4,575)	(5,110)
Pension and Post-Retirement Plans Losses
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(3,202)	(4,126)
Other comprehensive income (loss) before reclassifications	371	765
Amounts reclassified from accumulated other comprehensive loss	110	159
Other comprehensive (loss) income, net of tax	481	924	(614)
Ending balance	(2,721)	(3,202)	(4,126)
Foreign Currency Translation Adjustments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,373)	(984)
Other comprehensive income (loss) before reclassifications	(1,220)	(389)	559
Amounts reclassified from accumulated other comprehensive loss	0	0
Other comprehensive (loss) income, net of tax	(1,220)	(389)
Ending balance	$ (2,593)	$ (1,373)	$ (984)