Fair Value Measurements - Fair Value Option (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Fixed maturities, at fair value using the fair value option ("FVO Securities")	$ 292		$ 327
Changes in fair value of assets using fair value option	4	$ (8)
Fair Value, Option, Quantitative Disclosures [Line Items]
Fixed maturities, at fair value using the fair value option ("FVO Securities")	292		327
Collateralized Loan Obligations [Member]
Fair Value Disclosures [Abstract]
Fixed maturities, at fair value using the fair value option ("FVO Securities")	167		167
Fair Value, Option, Quantitative Disclosures [Line Items]
Fixed maturities, at fair value using the fair value option ("FVO Securities")	$ 167		$ 167