Shareholders' Equity - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 5,987	$ (3,325)	$ 5,457	$ (3,914)
Other comprehensive income/(loss) before reclassifications	59	198	(4)	312
Amounts reclassified from AOCI	75	23	149	64
Net current period Other comprehensive (loss)/income	134	221	145	376
Ending balance	6,115	(3,296)	6,115	(3,296)
Accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(10,266)	(10,760)	(10,277)	(10,915)
Ending balance	(10,132)	(10,539)	(10,132)	(10,539)
Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	1	(132)	64	(178)
Other comprehensive income/(loss) before reclassifications	35	62	(28)	108
Amounts reclassified from AOCI
Net current period Other comprehensive (loss)/income	35	62	(28)	108
Ending balance	36	(70)	36	(70)
Unrealized Gains and Losses on Certain Investments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	1	2	2	2
Other comprehensive income/(loss) before reclassifications			(1)
Amounts reclassified from AOCI
Net current period Other comprehensive (loss)/income			(1)
Ending balance	1	2	1	2
Unrealized Gains and Losses on Derivative Instruments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	74	(125)	88	(211)
Other comprehensive income/(loss) before reclassifications	24	138	16	206
Amounts reclassified from AOCI	(3)	10	(9)	28
Net current period Other comprehensive (loss)/income	21	148	7	234
Ending balance	95	23	95	23
Defined Benefit Pension Plans & Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(10,342)	(10,505)	(10,431)	(10,528)
Other comprehensive income/(loss) before reclassifications		(2)	9	(2)
Amounts reclassified from AOCI	78	13	158	36
Net current period Other comprehensive (loss)/income	78	11	167	34
Ending balance	$ (10,264)	$ (10,494)	$ (10,264)	$ (10,494)