Post-Employment Benefits - Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost — benefits earned during the year	$ 242	$ 230	$ 374
Interest cost on projected benefit obligations	469	455	300
Expected return on plans’ assets	(1,050)	(971)	(931)
Amortization of actuarial losses (gains)	24	11	231
Amortization of prior service costs (credits)	1	1	1
Total net cost (income)	(314)	(274)	(25)
Medical and Dental Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost — benefits earned during the year	39	38	50
Interest cost on projected benefit obligations	54	59	36
Expected return on plans’ assets	(24)	(23)	(30)
Amortization of actuarial losses (gains)	(2)	(2)	11
Amortization of prior service costs (credits)	(13)	(13)	(24)
Total net cost (income)	$ 54	$ 59	$ 43