Fair Values - Fund Interests Measured Based on Net Asset Value (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Measured Based on Net Asset Value
Carrying Value	$ 4,891	$ 4,747
Commitment	824	865
Private equity
Measured Based on Net Asset Value
Carrying Value	2,607	2,492
Commitment	579	615
Real estate
Measured Based on Net Asset Value
Carrying Value	2,089	2,064
Commitment	243	248
Hedge
Measured Based on Net Asset Value
Carrying Value	195	191
Commitment	$ 2	$ 2