Retirement Benefits (Reconciliation of Net Actuarial Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension  Benefits
Recognized as component of net benefit (credit) cost:
Total recognized as component of net benefit (credit) cost	$ (214)	$ (209)	$ (240)
Post-retirement Benefits
Recognized as component of net benefit (credit) cost:
Total recognized as component of net benefit (credit) cost	(2)	2	2
Net actuarial losses
Recognized as component of net benefit (credit) cost:
Amortization of net loss (gain)	20	150	208
U.S. | Net actuarial losses | Pension  Benefits
Reconciliation of unrecognized net actuarial gain loss [Roll Forward]
Beginning balance	(1,419)	(1,777)
Recognized as component of net benefit (credit) cost:
Amortization of net loss (gain)	19	74
Changes in plan assets and benefit obligations recognized in other comprehensive income (loss):
Other	(7)	0
Liability experience	20	1,625
Asset experience	40	(1,341)
Total amount recognized as change in plan assets and benefit obligations	53	284
Ending balance	(1,347)	(1,419)	(1,777)
U.S. | Net actuarial losses | Post-retirement Benefits
Reconciliation of unrecognized net actuarial gain loss [Roll Forward]
Beginning balance	8	3
Recognized as component of net benefit (credit) cost:
Amortization of net loss (gain)	(2)	0
Changes in plan assets and benefit obligations recognized in other comprehensive income (loss):
Other	0	2
Liability experience	(2)	3
Asset experience	0	0
Total amount recognized as change in plan assets and benefit obligations	(2)	5
Ending balance	4	8	3
Non-U.S. | Pension  Benefits
Recognized as component of net benefit (credit) cost:
Total recognized as component of net benefit (credit) cost	(182)	(140)	(187)
Non-U.S. | Post-retirement Benefits
Recognized as component of net benefit (credit) cost:
Total recognized as component of net benefit (credit) cost	(1)	1	2
Non-U.S. | Net actuarial losses | Pension  Benefits
Reconciliation of unrecognized net actuarial gain loss [Roll Forward]
Beginning balance	(2,610)	(2,904)
Recognized as component of net benefit (credit) cost:
Amortization of net loss (gain)	3	75
Effect of settlement	2	2
Total recognized as component of net benefit (credit) cost	5	77
Changes in plan assets and benefit obligations recognized in other comprehensive income (loss):
Liability experience	(226)	3,953
Asset experience	(191)	(4,051)
Total amount recognized as change in plan assets and benefit obligations	(417)	(98)
Exchange rate adjustments	(197)	315
Ending balance	(3,219)	(2,610)	(2,904)
Non-U.S. | Net actuarial losses | Post-retirement Benefits
Reconciliation of unrecognized net actuarial gain loss [Roll Forward]
Beginning balance	6	(10)
Recognized as component of net benefit (credit) cost:
Amortization of net loss (gain)	(1)	1
Effect of settlement	0	0
Total recognized as component of net benefit (credit) cost	(1)	1
Changes in plan assets and benefit obligations recognized in other comprehensive income (loss):
Liability experience	10	14
Asset experience	0	0
Total amount recognized as change in plan assets and benefit obligations	10	14
Exchange rate adjustments	2	1
Ending balance	$ 17	$ 6	$ (10)