Employee Benefits - Schedule of Fair Value of U.K. Plan Assets (Details) - Pension Plan - U.K. - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	$ 3,775	$ 3,537	$ 6,246
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	1,843	1,929
Significant Other Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	(255)	(548)
Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	1,510	1,403	$ 2,305
Cash and cash equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	273	336
Cash and cash equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	273	336
Cash and cash equivalents | Significant Other Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Cash and cash equivalents | Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Equity investments, Pooled funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Equity investments, Pooled funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Equity investments, Pooled funds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Equity investments, Pooled funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Derivatives
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	(255)	(548)
Derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Derivatives | Significant Other Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	(255)	(548)
Derivatives | Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Government and agency bonds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	1,570	1,593
Government and agency bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	1,570	1,593
Government and agency bonds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Government and agency bonds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Annuities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	1,510	1,403
Annuities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Annuities | Significant Other Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Annuities | Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	1,510	1,403
Fixed Income Investments, Pooled Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	160	139
Fixed Income Investments, Pooled Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Fixed Income Investments, Pooled Funds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Fixed Income Investments, Pooled Funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Real estate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	92	97
Real estate | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Real estate | Significant Other Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Real estate | Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Other Investments, Pooled Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	425	517
Other Investments, Pooled Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Other Investments, Pooled Funds | Significant Other Observable Inputs (Level 2)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	0	0
Other Investments, Pooled Funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined benefit plan, plan assets	$ 0	$ 0