Post-Employment Benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Defined Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	$ 92	$ 98	$ 282	$ 294
Interest cost on projected benefit obligations	74	62	225	186
Expected return on plan assets	(231)	(211)	(701)	(633)
Net amortization of:
Actuarial loss, net	58	79	174	238
Prior service cost (credit)	0	0	1	1
Net cost (credit)	(7)	28	(19)	86
Medical and Dental Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost - benefits earned during the period	13	14	38	42
Interest cost on projected benefit obligations	9	8	27	25
Expected return on plan assets	(8)	(6)	(23)	(20)
Net amortization of:
Actuarial loss, net	2	7	8	21
Prior service cost (credit)	(6)	(7)	(18)	(21)
Net cost (credit)	$ 10	$ 16	$ 32	$ 47