Employee Benefit Plans - Schedule of Pre-tax Change in Other Comprehensive Loss (Income) (Details) - Pension Benefits - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Recognized in the Balance Sheet
(Gains) Losses	$ (75)	$ 141
Expense Recognized in the Income Statement
Amortization of Net Loss	29	50	$ 73
Settlement Loss	$ 0	$ 1	$ 0