Fair Value - Gross Transfers Into (Out of) Level 3 (Details) - Recurring - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net transfers out of Level 3	$ (50)	$ (29)
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross transfers into Level 3	0	0
Gross transfers out of Level 3	(50)	(29)
Net transfers out of Level 3	$ (50)	$ (29)