Other Comprehensive Income (Loss) (Schedule of Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	$ 11,222
Other comprehensive loss, net of tax	(104)	$ (87)
Balance, end of period	11,156	9,596
AOCI Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(4,575)	(5,110)
Other comprehensive income (loss), before reclassification, net of tax	(134)	(127)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	30	40
Other comprehensive loss, net of tax	(104)	(87)
Balance, end of period	(4,679)	(5,197)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(3,202)	(4,126)
Other comprehensive income (loss), before reclassification, net of tax	35	(36)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	30	40
Other comprehensive loss, net of tax	65	4
Balance, end of period	(3,137)	(4,122)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, beginning of period	(1,373)	(984)
Other comprehensive income (loss), before reclassification, net of tax	(169)	(91)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0
Other comprehensive loss, net of tax	(169)	(91)
Balance, end of period	$ (1,542)	$ (1,075)