Investments - Schedule of Carrying Value for Limited Partnership Interests (Details) - USD ($) $ in Millions	Mar. 31, 2025	Dec. 31, 2024
Debt and Equity Securities, FV-NI [Line Items]
Limited partnership interests	$ 9,380	$ 9,255
Private equity
Debt and Equity Securities, FV-NI [Line Items]
Limited partnership interests	7,744	7,734
Real estate
Debt and Equity Securities, FV-NI [Line Items]
Limited partnership interests	1,355	1,236
Other
Debt and Equity Securities, FV-NI [Line Items]
Limited partnership interests	$ 281	$ 285