Investments - Debt Securities by Maturity (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Net Amortized Cost
Less than one year	$ 1,221
One year through five years	6,807
After five years through ten years	5,031
Greater than ten years	4,391
Net Amortized Cost	22,201	$ 22,174
Fair Value
Less than one year	1,221
One year through five years	6,503
After five years through ten years	4,559
Greater than ten years	4,022
Total	20,751	23,240
Residential mortgage-backed securities
Net Amortized Cost
Debt securities, maturity, without single maturity date	808
Net Amortized Cost	808	870
Fair Value
Debt securities, maturity, without single maturity date	747
Total	747	875
Commercial mortgage-backed securities
Net Amortized Cost
Debt securities, maturity, without single maturity date	1,222
Net Amortized Cost	1,222	1,278
Fair Value
Debt securities, maturity, without single maturity date	1,108
Total	1,108	1,310
Other asset-backed securities
Net Amortized Cost
Debt securities, maturity, without single maturity date	2,721
Net Amortized Cost	2,721	2,791
Fair Value
Debt securities, maturity, without single maturity date	2,591
Total	$ 2,591	$ 2,792