Post-Employment Benefits - Schedule of Net Periodic Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Defined Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	$ 61	$ 60
Interest cost on projected benefit obligations	118	114
Expected return on plan assets	(262)	(242)
Net amortization of:
Actuarial loss, net	6	3
Prior service cost (credit)	0	0
Net cost (credit)	(77)	(65)
Medical and Dental Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	10	9
Interest cost on projected benefit obligations	15	14
Expected return on plan assets	(6)	(6)
Net amortization of:
Actuarial loss, net	0	0
Prior service cost (credit)	(3)	(3)
Net cost (credit)	$ 16	$ 14