Shareholders' Equity - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance				$ (10,305)
Other comprehensive (loss)/income before reclassifications	[1]	$ 1	$ (48)	(113)	$ (21)
Amounts reclassified from AOCI	[1]	19	(19)	26	(46)
Net current period Other comprehensive loss	[1]	20	(67)	(87)	(67)
Ending balance		(10,392)		(10,392)
Other comprehensive (income) loss, defined benefit plan, reclassification adjustment from AOCI, after tax		0	(22)	0	(44)
Other comprehensive (income) loss, defined benefit plan, reclassification adjustment from AOCI, tax		0	(7)	0	(13)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	[1]	(10,412)	(9,550)	(10,305)	(9,550)
Ending balance	[1]	(10,392)	(9,617)	(10,392)	(9,617)
Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(169)	(151)	(134)	(167)
Other comprehensive (loss)/income before reclassifications		11	(6)	(24)	10
Amounts reclassified from AOCI
Net current period Other comprehensive loss		11	(6)	(24)	10
Ending balance		(158)	(157)	(158)	(157)
Unrealized Gains and Losses on Certain Investments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		2		2
Other comprehensive (loss)/income before reclassifications
Amounts reclassified from AOCI
Net current period Other comprehensive loss
Ending balance		2		2
Unrealized Gains and Losses on Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(46)	(11)	12	(24)
Other comprehensive (loss)/income before reclassifications		(11)	(43)	(76)	(25)
Amounts reclassified from AOCI		19	3	26	(2)
Net current period Other comprehensive loss		8	(40)	(50)	(27)
Ending balance		(38)	(51)	(38)	(51)
Defined Benefit Pension Plans & Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance		(10,199)	(9,388)	(10,185)	(9,359)
Other comprehensive (loss)/income before reclassifications		1	1	(13)	(6)
Amounts reclassified from AOCI			(22)		(44)
Net current period Other comprehensive loss		1	(21)	(13)	(50)
Ending balance		$ (10,198)	$ (9,409)	$ (10,198)	$ (9,409)

[1] Net of tax. (2)    Primarily relates to the amortization of prior service credits and actuarial losses/(gains) included in net periodic benefit cost for the six and three months ended June 30, 2024 totaling $0 and $0 (net of tax of $0 and $0), and ($44) and ($22) (net of tax of $13 and $7) for the same periods in prior year.