Changes in Accumulated Other Comprehensive Losses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 160,242	$ 139,940
Components of Other Comprehensive Income (Loss):
Other Comprehensive Gain (Loss), Net of Tax	57	237
Ending balance	160,434	147,100
Related income taxes	2,914	2,777
Total
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(2,798)	(3,889)
Components of Other Comprehensive Income (Loss):
Before Reclassifications	7	108
Reclassifications	50	129
Other Comprehensive Gain (Loss), Net of Tax	57	237
Ending balance	(2,741)	(3,652)
Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(203)	(162)
Components of Other Comprehensive Income (Loss):
Before Reclassifications	7	(11)
Reclassifications	0	0
Other Comprehensive Gain (Loss), Net of Tax	7	(11)
Ending balance	(196)	(173)
Unrealized Holding Gains (Losses) on Securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(12)	(11)
Components of Other Comprehensive Income (Loss):
Before Reclassifications	(4)	0
Reclassifications	0	0
Other Comprehensive Gain (Loss), Net of Tax	(4)	0
Ending balance	(16)	(11)
Derivatives
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(12)	0
Components of Other Comprehensive Income (Loss):
Before Reclassifications	(2)	2
Reclassifications	15	0
Other Comprehensive Gain (Loss), Net of Tax	13	2
Ending balance	1	2
Defined Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(2,571)	(3,716)
Components of Other Comprehensive Income (Loss):
Before Reclassifications	6	117
Reclassifications	35	129
Other Comprehensive Gain (Loss), Net of Tax	41	246
Ending balance	(2,530)	$ (3,470)
Defined Benefit Plans | Reclassification out of Accumulated Other Comprehensive Income
Components of Other Comprehensive Income (Loss):
Employee Benefits for reclassified components	45
Related income taxes	$ 10