Fair Value of Financial Instruments - Changes in Unrealized Gains (Losses) Included in OCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Corporate bonds
Fair Value Assets and Liabilities Measured on Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	$ (36)	$ (10)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Unrealized investment gain (loss)
CMBS
Fair Value Assets and Liabilities Measured on Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	$ (1)	0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Unrealized investment gain (loss)
ABS
Fair Value Assets and Liabilities Measured on Recurring Basis Level 3 Activity [Line Items]
Unrealized gains (losses) included in OCI, net	$ (39)	16
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Unrealized investment gain (loss)
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	$ (1)	0
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Unrealized investment gain (loss)
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	$ (1)	$ 1
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Unrealized investment gain (loss)