Shareholders' Equity - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ (3,296)	$ (17,982)	$ (3,914)	$ (17,228)
Other comprehensive income/(loss) before reclassifications	(26)	119	286	6
Amounts reclassified from AOCI	21		85	26
Net current period Other comprehensive (loss)/income	(5)	119	371	32
Ending balance	(8,253)	(23,562)	(8,253)	(23,562)
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(10,539)	(10,392)	(10,915)	(10,305)
Ending balance	(10,544)	(10,273)	(10,544)	(10,273)
Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(70)	(158)	(178)	(134)
Other comprehensive income/(loss) before reclassifications	(1)	54	107	30
Amounts reclassified from AOCI
Net current period Other comprehensive (loss)/income	(1)	54	107	30
Ending balance	(71)	(104)	(71)	(104)
Unrealized Gains and Losses on Certain Investments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	2	2	2	2
Other comprehensive income/(loss) before reclassifications		1		1
Amounts reclassified from AOCI
Net current period Other comprehensive (loss)/income		1		1
Ending balance	2	3	2	3
Unrealized Gains and Losses on Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	23	(38)	(211)	12
Other comprehensive income/(loss) before reclassifications	(25)	63	181	(13)
Amounts reclassified from AOCI	4		32	26
Net current period Other comprehensive (loss)/income	(21)	63	213	13
Ending balance	2	25	2	25
Defined Benefit Pension Plans & Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(10,494)	(10,198)	(10,528)	(10,185)
Other comprehensive income/(loss) before reclassifications		1	(2)	(12)
Amounts reclassified from AOCI	17		53
Net current period Other comprehensive (loss)/income	17	1	51	(12)
Ending balance	$ (10,477)	$ (10,197)	$ (10,477)	$ (10,197)