Fair Value of Financial Instruments - Changes in Unrealized Gains (Losses) Included in OCI (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Fair Value Assets And Liabilities Measured On Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	$ (10)	$ (50)	$ 1	$ (59)
Corporate bonds
Fair Value Assets And Liabilities Measured On Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	(7)	(29)	(14)	(41)
ABS
Fair Value Assets And Liabilities Measured On Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	(5)	(20)	11	(20)
Hybrid and redeemable preferred securities
Fair Value Assets And Liabilities Measured On Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	0	(1)	0	1
Mortgage loans on real estate
Fair Value Assets And Liabilities Measured On Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	$ 2	$ 0	$ 4	$ 1