Other Comprehensive (Loss) Income (Accumulated Other Comprehensive (Loss) Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period			$ 12,370
Other comprehensive income (loss), net of tax	$ 537	$ (405)	305	$ (146)
Balance, end of period	13,882	11,586	13,882	11,586
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(5,527)	(5,055)	(5,295)	(5,314)
Other comprehensive (loss) income before reclassifications	533	(409)	292	(156)
Amounts reclassified from accumulated other comprehensive income	4	4	13	10
Other comprehensive income (loss), net of tax	537	(405)	305	(146)
Balance, end of period	(4,990)	(5,460)	(4,990)	(5,460)
Pension/Post-Retirement Plans Gains (Losses)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(3,050)	(2,811)	(3,101)	(2,721)
Other comprehensive (loss) income before reclassifications	(135)	76	(93)	(20)
Amounts reclassified from accumulated other comprehensive income	4	4	13	10
Other comprehensive income (loss), net of tax	(131)	80	(80)	(10)
Balance, end of period	(3,181)	(2,731)	(3,181)	(2,731)
Deferred tax assets, net	1,500	1,300	1,500	1,300
Foreign Currency Translation Adjustments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(2,477)	(2,244)	(2,194)	(2,593)
Other comprehensive (loss) income before reclassifications	668	(485)	385	(136)
Amounts reclassified from accumulated other comprehensive income	0	0	0	0
Other comprehensive income (loss), net of tax	668	(485)	385	(136)
Balance, end of period	$ (1,809)	$ (2,729)	$ (1,809)	$ (2,729)