Investments - Scheduled maturities of available for sale fixed maturities (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Fiscal Year Maturity [Abstract]
Available for sale (AFS) fixed maturities	$ 9,931	$ 10,095
Fair Value Percent, Fiscal Year Maturity [Abstract]
Average life of ABS	3 years
Average life of MBS	6 years 6 months
Fixed maturities:
Amortized Cost Basis, Fiscal Year Maturity [Abstract]
One year or less	$ 413
After one year through five years	2,649
After five years through ten years	1,099
After ten years	348
Fixed maturities amortized cost, Subtotal	4,509
Amortized Cost	10,590
Fair Value, Fiscal Year Maturity [Abstract]
One year or less	404
After one year through five years	2,495
After five years through ten years	1,022
After ten years	315
Fixed maturities fair value, Subtotal	4,236
Available for sale (AFS) fixed maturities	$ 9,931	$ 10,095
Fair Value Percent, Fiscal Year Maturity [Abstract]
One year or less	4.00%
After one year through five years	25.00%
After five years through ten years	11.00%
After ten years	3.00%
Fixed maturities fair value, Subtotal, Percent	43.00%
Fair value, Total, Percent	100.00%
Collateralized loan obligations and other asset backed securities
Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Fixed maturities without single maturity date	$ 4,190
Fair Value, Fiscal Year Maturity [Abstract]
Fixed maturities without single maturity date	$ 4,000
Fair Value Percent, Fiscal Year Maturity [Abstract]
Fixed maturities without single maturity date	40.00%
Mortgage-backed securities
Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Fixed maturities without single maturity date	$ 1,891
Fair Value, Fiscal Year Maturity [Abstract]
Fixed maturities without single maturity date	$ 1,695
Fair Value Percent, Fiscal Year Maturity [Abstract]
Fixed maturities without single maturity date	17.00%