Changes in Accumulated Other Comprehensive Losses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 160,263	$ 159,298	$ 161,929	$ 160,242
Components of Other Comprehensive Income (Loss):
Other Comprehensive Gain (Loss), Net of Tax	99	114	135	201
Ending balance	157,030	166,248	157,030	166,248
Related income taxes	1,993	2,183	6,957	6,926
Total
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(2,924)	(2,711)	(2,960)	(2,798)
Components of Other Comprehensive Income (Loss):
Before Reclassifications			(37)	8
Reclassifications			172	193
Other Comprehensive Gain (Loss), Net of Tax	99	114	135	201
Ending balance	(2,825)	(2,597)	(2,825)	(2,597)
Currency Translation Adjustment
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			(192)	(203)
Components of Other Comprehensive Income (Loss):
Before Reclassifications			(9)	(21)
Reclassifications			0	0
Other Comprehensive Gain (Loss), Net of Tax			(9)	(21)
Ending balance	(201)	(224)	(201)	(224)
Unrealized Holding Gains (Losses) on Securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			(11)	(12)
Components of Other Comprehensive Income (Loss):
Before Reclassifications			(5)	(4)
Reclassifications			0	0
Other Comprehensive Gain (Loss), Net of Tax			(5)	(4)
Ending balance	(16)	(16)	(16)	(16)
Derivatives
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			5	(12)
Components of Other Comprehensive Income (Loss):
Before Reclassifications			(36)	(18)
Reclassifications			43	17
Other Comprehensive Gain (Loss), Net of Tax			7	(1)
Ending balance	12	(13)	12	(13)
Defined Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance			(2,762)	(2,571)
Components of Other Comprehensive Income (Loss):
Before Reclassifications			13	51
Reclassifications			129	176
Other Comprehensive Gain (Loss), Net of Tax			142	227
Ending balance	$ (2,620)	$ (2,344)	(2,620)	$ (2,344)
Defined Benefit Plans | Reclassification out of Accumulated Other Comprehensive Income
Components of Other Comprehensive Income (Loss):
Employee Benefits for reclassified components			177
Related income taxes			$ 48