Investments - Schedule of Carrying Value for Limited Partnership Interests (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Debt and Equity Securities, FV-NI [Line Items]
Limited partnership interests	$ 8,730	$ 8,380
Private equity
Debt and Equity Securities, FV-NI [Line Items]
Limited partnership interests	7,426	7,154
Real estate
Debt and Equity Securities, FV-NI [Line Items]
Limited partnership interests	1,142	1,085
Other
Debt and Equity Securities, FV-NI [Line Items]
Limited partnership interests	$ 162	$ 141