Investments - Distribution of Residential Mortgage Loans by State (Details) - USD ($) $ in Millions	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Schedule of Investments [Line Items]
Allowance for expected credit loss	$ (64)	$ (67)	$ (66)	$ (64)	$ (60)	$ (42)
Total loans net of valuation allowance	5,439		5,336
Residential Mortgages
Schedule of Investments [Line Items]
Amortized Cost	2,929		2,852
Allowance for expected credit loss	(50)	$ (54)	(54)	$ (51)	$ (48)	$ (32)
Total loans net of valuation allowance	$ 2,879		$ 2,798
% of Total	100.00%		100.00%
Florida | Residential Mortgages
Schedule of Investments [Line Items]
Amortized Cost	$ 157		$ 163
% of Total	5.00%		6.00%
California | Residential Mortgages
Schedule of Investments [Line Items]
Amortized Cost	$ 137
% of Total	5.00%
New York | Residential Mortgages
Schedule of Investments [Line Items]
Amortized Cost			$ 129
% of Total			5.00%
Texas | Residential Mortgages
Schedule of Investments [Line Items]
Amortized Cost			$ 129
% of Total			5.00%
All other states | Residential Mortgages
Schedule of Investments [Line Items]
Amortized Cost	$ 2,635		$ 2,431
% of Total	90.00%		84.00%