Employee Benefit Plans - Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Other Postretirement
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	$ 614	$ 769
Employer contributions	6	8
Participant contributions	8	8
Actual return on plan assets	86	(122)
Settlement	0	0
Benefits paid	(49)	(49)
Ending balance	665	614	$ 769
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	569	714
Service cost	8	11	12
Interest cost	30	20	19
Participant contributions	8	8
Actuarial loss (gain)	(1)	(155)
Amendment	0	20
Curtailment	0	0
Settlement	0	0
Benefits paid	(49)	(49)
Ending balance	565	569	714
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Plan assets at fair value, end of year	665	614	769
Benefit obligation, end of year	565	569	714
Funded status	100	45
Other assets	104	52
Other current liabilities	0	0
Other long-term liabilities	(4)	(7)
Amounts recognized	100	45
Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract]
Fair value of plan assets	0	240
Projected benefit obligation	4	247
Supplemental Employee Retirement Plan
Defined Benefit Plans, Supplemental Employee Retirement Plans [Abstract]
Rabbi trusts	341	300
U.S. | Pension
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	2,013	2,795
Employer contributions	14	14
Participant contributions	0	0
Actual return on plan assets	219	(491)
Settlement	0	(164)
Benefits paid	(177)	(141)
Ending balance	2,069	2,013	2,795
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	2,040	2,777
Service cost	15	22	30
Interest cost	110	83	78
Participant contributions	0	0
Actuarial loss (gain)	62	(524)
Amendment	0	(3)
Curtailment	0	(10)
Settlement	0	(164)
Benefits paid	(177)	(141)
Ending balance	2,050	2,040	2,777
Accumulated benefit obligation, end of year	2,013	2,003
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Plan assets at fair value, end of year	2,069	2,013	2,795
Benefit obligation, end of year	2,050	2,040	2,777
Funded status	19	(27)
Other assets	160	125
Other current liabilities	(13)	(13)
Other long-term liabilities	(128)	(139)
Amounts recognized	19	(27)
Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract]
Fair value of plan assets	0	490
Projected benefit obligation	141	643
Fair value of plan assets	0	0
Accumulated benefit obligation	141	142
United Kingdom | Pension
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	1,363	2,363
Employer contributions	13	15
Participant contributions	1	1
Actual return on plan assets	52	(671)
Benefits paid	(97)	(109)
Foreign currency exchange rate changes	70	(236)
Ending balance	1,402	1,363	2,363
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	1,175	2,003
Service cost	6	14	16
Interest cost	57	35	31
Participant contributions	1	1
Actuarial loss (gain)	1	(596)
Amendment	16	27
Benefits paid	(97)	(109)
Foreign currency exchange rate changes	60	(200)
Ending balance	1,219	1,175	2,003
Accumulated benefit obligation, end of year	1,103	1,060
Defined Benefit Plan, Funded (Unfunded) Status of Plan [Abstract]
Plan assets at fair value, end of year	1,402	1,363	2,363
Benefit obligation, end of year	1,219	1,175	$ 2,003
Funded status	183	188
Other assets	$ 183	$ 188