Derivative Financial Instruments - Collateral (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Payables under securities loan agreement, including collateral held | Over the Counter
Derivatives, Fair Value [Line Items]
Securities held as collateral	$ 33	$ 84
Payables under securities loan agreement, including collateral held | Cleared Derivative Contract
Derivatives, Fair Value [Line Items]
Securities held as collateral	56	147
Securities pledged
Derivatives, Fair Value [Line Items]
Securities held as collateral	4	11
Securities pledged as collateral	$ 159	$ 201