Investments - Scheduled maturities of available for sale fixed maturities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Fiscal Year Maturity [Abstract]
Available for sale (AFS) fixed maturities	$ 10,377	$ 10,095
Fair Value Percent, Fiscal Year Maturity [Abstract]
Collateralized loan obligations and other asset-backed securities average life	3 years
Average life of MBS	6 years 6 months
Fixed maturities
Amortized Cost Basis, Fiscal Year Maturity [Abstract]
One year or less	$ 531
After one year through five years	2,744
After five years through ten years	1,147
After ten years	278
Fixed maturities amortized cost, Subtotal	4,700
Amortized cost	10,740
Fair Value, Fiscal Year Maturity [Abstract]
One year or less	521
After one year through five years	2,663
After five years through ten years	1,143
After ten years	269
Fixed maturities fair value, Subtotal	4,596
Available for sale (AFS) fixed maturities	$ 10,377	$ 10,095
Fair Value Percent, Fiscal Year Maturity [Abstract]
One year or less	5.00%
After one year through five years	26.00%
After five years through ten years	11.00%
After ten years	2.00%
Fixed maturities fair value, Subtotal, Percent	44.00%
Fair value, Total, Percent	100.00%
Collateralized loan obligations and other asset backed securities
Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Fixed maturities without a single maturity date	$ 4,178
Fair Value, Fiscal Year Maturity [Abstract]
Fixed maturities without a single maturity date	$ 4,049
Fair Value Percent, Fiscal Year Maturity [Abstract]
Fixed maturities without a single maturity date, percent of fair value	39.00%
Mortgage-backed securities
Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Fixed maturities without a single maturity date	$ 1,862
Fair Value, Fiscal Year Maturity [Abstract]
Fixed maturities without a single maturity date	$ 1,732
Fair Value Percent, Fiscal Year Maturity [Abstract]
Fixed maturities without a single maturity date, percent of fair value	17.00%