Fair Value of Financial Instruments - Components of the Transfers In and Out of Level 3 (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers Into Level 3	$ 53	$ 71
Transfers Out of Level 3	(123)	(236)
Total	(70)	(165)
Corporate bonds
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers Into Level 3	22	59
Transfers Out of Level 3	(44)	(43)
Total	(22)	16
State and municipal bonds
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers Into Level 3	0	0
Transfers Out of Level 3	(5)	0
Total	(5)	0
ABS
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers Into Level 3	31	0
Transfers Out of Level 3	(23)	(193)
Total	8	(193)
Hybrid and redeemable preferred securities
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers Into Level 3	0	12
Transfers Out of Level 3	0	0
Total	0	12
Derivative investments
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
Transfers Into Level 3	0	0
Transfers Out of Level 3	(51)	0
Total	$ (51)	$ 0