Pension and Postretirement Benefit Plans and Defined Contribution Plans - Schedule of Net Periodic Benefit Costs (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		$ 12	$ 29	$ 36
Interest cost		21	27	29
Expected return on plan assets		(44)	(47)	(39)
Amortization of prior service cost/(credit)		(119)	(130)	(151)
Actuarial (gains)/losses	[1]	51	(440)	(167)
Curtailments		(12)	(18)	(82)
Special termination benefits		0	1	2
Net periodic benefit cost/(credit) reported in income		(90)	(578)	(372)
Cost/(credit) reported in Other comprehensive income/(loss)		128	169	107
Cost/(credit) recognized in Comprehensive income		38	(410)	(265)
U.S. [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		0	0	0
Interest cost		589	534	455
Expected return on plan assets		(778)	(862)	(1,052)
Amortization of prior service cost/(credit)		2	2	(2)
Actuarial (gains)/losses	[1]	(410)	225	(684)
Curtailments		0	0	0
Special termination benefits		6	18	17
Net periodic benefit cost/(credit) reported in income		(592)	(84)	(1,265)
Cost/(credit) reported in Other comprehensive income/(loss)		(2)	(2)	2
Cost/(credit) recognized in Comprehensive income		(594)	(86)	(1,264)
International [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		85	116	130
Interest cost		287	157	146
Expected return on plan assets		(304)	(296)	(327)
Amortization of prior service cost/(credit)		0	(1)	(1)
Actuarial (gains)/losses	[1]	102	(11)	(690)
Curtailments		(2)	(11)	(4)
Special termination benefits		0	1	0
Net periodic benefit cost/(credit) reported in income		169	(45)	(746)
Cost/(credit) reported in Other comprehensive income/(loss)		31	(1)	4
Cost/(credit) recognized in Comprehensive income		$ 199	$ (46)	$ (742)

[1] Reflects: (i) actuarial remeasurement net gains in 2023, primarily due to favorable asset performance in the U.S. and increases in discount rates for the international plans, partially offset by unfavorable asset performance for certain international plans, (ii) actuarial remeasurement net gains in 2022, primarily due to increases in discount rates, partially offset by unfavorable plan asset performance, and (iii) actuarial remeasurement gains in 2021, primarily due to favorable plan asset performance and increases in discount rates.