Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022	Dec. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	$ (7,261)	$ (9,582)	$ (7,261)	$ (9,582)		$ (7,139)
Other Comprehensive Income (Loss), Net of Tax	(194)	(378)	(122)	(605)
Derivative instruments	(25)	22	(45)	491
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(181)	(312)	(181)	(312)	$ (161)	(253)	$ (190)	$ 59
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(33)	(61)	55	(385)
Other Comprehensive Income (Loss), Tax	9	(55)	48	12
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(24)	(116)	103	(373)
Other Comprehensive Income (Loss), Net of Tax	(20)	(122)	72	(371)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	4	(8)	(41)	2
Reclassification from AOCI, Current Period, Tax	0	2	10	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	4	(6)	(31)	2
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(2,083)	(2,436)	(2,083)	(2,436)	(1,936)	(1,934)	(2,033)	(1,355)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(122)	(369)	(122)	(1,034)
Other Comprehensive Income (Loss), Tax	(6)	(17)	(16)	(7)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(128)	(386)	(138)	(1,041)
Other Comprehensive Income (Loss), Net of Tax	(147)	(403)	(149)	(1,081)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(19)	(17)	(11)	(40)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(4,877)	(6,978)	(4,877)	(6,978)	(4,875)	(4,877)	(7,103)	(7,334)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(4)	6	(7)	11
Other Comprehensive Income (Loss), Net of Tax	(2)	125	0	356
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	3	155	8	468
Reclassification from AOCI, Current Period, Tax	(1)	(36)	(1)	(123)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2	119	7	345
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive loss	(120)	144	(120)	144	$ (95)	$ (75)	$ 122	$ (347)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(58)	122	(242)	802
Other Comprehensive Income (Loss), Tax	(2)	(31)	34	(114)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(60)	91	(208)	688
Derivative instruments	(25)	22	(45)	491
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	45	(80)	209	(222)
Reclassification from AOCI, Current Period, Tax	(10)	11	(46)	25
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ 35	$ (69)	$ 163	$ (197)