Retirement Benefits - Net Periodic Cost (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Postretirement Health Care Benefits Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 0
Interest cost	5	2	1
Expected return on plan assets	(13)	(12)	(11)
Amortization of:
Unrecognized net loss	2	4	3
Unrecognized prior service benefit	3	0	(5)
Net periodic cost (benefit)	(3)	(6)	(12)
United States | Pension Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0
Interest cost	190	128	115
Expected return on plan assets	(293)	(254)	(235)
Amortization of:
Unrecognized net loss	22	62	70
Unrecognized prior service benefit	0	0	0
Net periodic cost (benefit)	(81)	(64)	(50)
Non U.S. | Pension Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	1
Interest cost	56	29	21
Expected return on plan assets	(108)	(93)	(99)
Amortization of:
Unrecognized net loss	37	14	16
Unrecognized prior service benefit	(2)	(2)	(3)
Net periodic cost (benefit)	$ (16)	$ (51)	$ (64)