Employee Retirement Benefits - Fair Value of Pension Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Equity Securities [Member]
Fair value measurements of plan assets [Abstract]
Foreign investments	$ 591	$ 526
Equity Securities [Member] | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	1,450	1,252
Equity Securities [Member] | Level 1 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	1,444	1,246
Equity Securities [Member] | Level 2 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	5	5
Equity Securities [Member] | Level 3 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	1	1
Equity Commingled Vehicles [Member]
Fair value measurements of plan assets [Abstract]
Foreign investments	222	191
Equity Commingled Vehicles [Member] | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	754	731
Equity Commingled Vehicles [Member] | Level 1 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	0	0
Equity Commingled Vehicles [Member] | Level 2 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	754	731
Equity Commingled Vehicles [Member] | Level 3 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	0	0
U.S. Government And Municipal Bonds [Member] | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	101	90
U.S. Government And Municipal Bonds [Member] | Level 1 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	96	85
U.S. Government And Municipal Bonds [Member] | Level 2 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	5	5
U.S. Government And Municipal Bonds [Member] | Level 3 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	0	0
Corporate debt securities [Member]
Fair value measurements of plan assets [Abstract]
Foreign investments	72	83
Corporate debt securities [Member] | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	252	272
Corporate debt securities [Member] | Level 1 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	0	0
Corporate debt securities [Member] | Level 2 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	252	272
Corporate debt securities [Member] | Level 3 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	0	0
Asset-backed securities [Member]
Fair value measurements of plan assets [Abstract]
Foreign investments	157	129
Asset-backed securities [Member] | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	500	413
Asset-backed securities [Member] | Level 1 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	0	0
Asset-backed securities [Member] | Level 2 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	500	413
Asset-backed securities [Member] | Level 3 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	0	0
Debt Security Commingled Vehicles [Member]
Fair value measurements of plan assets [Abstract]
Foreign investments	2
Debt Security Commingled Vehicles [Member] | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	184	130
Debt Security Commingled Vehicles [Member] | Level 1 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	0	0
Debt Security Commingled Vehicles [Member] | Level 2
Fair value measurements of plan assets [Abstract]
Fair value	184	130
Debt Security Commingled Vehicles [Member] | Level 3
Fair value measurements of plan assets [Abstract]
Fair value	0	0
Convertible securities [Member]
Fair value measurements of plan assets [Abstract]
Foreign investments	21	30
Convertible securities [Member] | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	255	417
Convertible securities [Member] | Level 1 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	8	50
Convertible securities [Member] | Level 2 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	247	367
Convertible securities [Member] | Level 3 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	0	0
Other Security Investments
Fair value measurements of plan assets [Abstract]
Foreign investments	2
Other Security Investments | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	8
Other Security Investments | Level 1 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	6
Other Security Investments | Level 2 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	2
Other Security Investments | Level 3 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	0
Total Investments
Fair value measurements of plan assets [Abstract]
Fair value	4,897	4,543
Total Investments | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	3,504	3,305
Total Investments | Level 1 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	1,554	1,381
Total Investments | Level 2 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	1,949	1,923
Total Investments | Level 3 | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	1	1
Total Investments | Fair Value Measured at Net Asset Value Per Share | Carrying Amount
Fair value measurements of plan assets [Abstract]
Fair value	1,393	1,238
Investments measured at net asset value [Member]
Fair value measurements of plan assets [Abstract]
Foreign investments	$ 240	$ 242