Post-Employment Benefits - Plan Assets Measured at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	$ 13,373	$ 11,675
U.S. large cap
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	3,425	2,866
U.S. mid and small cap
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	814	693
International
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	2,725	2,401
U.S. government securities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	391	362
Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	1,519	1,318
Non-U.S. government securities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	586	419
Other, asset backed securities, bank loans, interest rate swap positions and diversified fixed income vehicles
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	863	775
Absolute return funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	1,669	1,678
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	276	154
Other, private funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	1,105	1,009
Quoted Prices in Active Markets
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	4,384	3,750
Quoted Prices in Active Markets | U.S. large cap
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	2,305	1,840
Quoted Prices in Active Markets | U.S. mid and small cap
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	807	684
Quoted Prices in Active Markets | International
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	493	454
Quoted Prices in Active Markets | U.S. government securities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	5	5
Quoted Prices in Active Markets | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	125	123
Quoted Prices in Active Markets | Non-U.S. government securities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	36	16
Quoted Prices in Active Markets | Other, asset backed securities, bank loans, interest rate swap positions and diversified fixed income vehicles
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	322	297
Quoted Prices in Active Markets | Absolute return funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	270	304
Quoted Prices in Active Markets | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	16	20
Quoted Prices in Active Markets | Other, private funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	5	7
Significant Other Observable Inputs
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	1,535	1,306
Significant Other Observable Inputs | U.S. large cap
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Significant Other Observable Inputs | U.S. mid and small cap
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Significant Other Observable Inputs | International
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Significant Other Observable Inputs | U.S. government securities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	371	341
Significant Other Observable Inputs | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	1,055	890
Significant Other Observable Inputs | Non-U.S. government securities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	3	0
Significant Other Observable Inputs | Other, asset backed securities, bank loans, interest rate swap positions and diversified fixed income vehicles
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	106	75
Significant Other Observable Inputs | Absolute return funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Significant Other Observable Inputs | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Significant Other Observable Inputs | Other, private funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Significant Unobservable Inputs
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	1	1
Significant Unobservable Inputs | U.S. large cap
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Significant Unobservable Inputs | U.S. mid and small cap
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	1	1
Significant Unobservable Inputs | International
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Significant Unobservable Inputs | U.S. government securities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Significant Unobservable Inputs | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Significant Unobservable Inputs | Non-U.S. government securities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Significant Unobservable Inputs | Other, asset backed securities, bank loans, interest rate swap positions and diversified fixed income vehicles
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Significant Unobservable Inputs | Absolute return funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Significant Unobservable Inputs | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Significant Unobservable Inputs | Other, private funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	0	0
Measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	7,453	6,618
Measured at NAV | U.S. large cap
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	1,120	1,026
Measured at NAV | U.S. mid and small cap
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	6	8
Measured at NAV | International
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	2,232	1,947
Measured at NAV | U.S. government securities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	15	16
Measured at NAV | Corporate debt instruments
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	339	305
Measured at NAV | Non-U.S. government securities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	547	403
Measured at NAV | Other, asset backed securities, bank loans, interest rate swap positions and diversified fixed income vehicles
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	435	403
Measured at NAV | Absolute return funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	1,399	1,374
Measured at NAV | Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	260	134
Measured at NAV | Other, private funds
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, plan assets measured at fair value	$ 1,100	$ 1,002