Investments - Scheduled maturities of available for sale fixed maturities (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Fair Value, Fiscal Year Maturity [Abstract]
Available for sale (AFS) fixed maturities	$ 10,196	$ 10,377
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	$ 414
After one year through five years	2,857
After five years through ten years	1,226
After ten years	284
Fixed maturities amortized cost, Subtotal	4,781
Amortized cost	10,563
Fair Value, Fiscal Year Maturity [Abstract]
One year or less	404
After one year through five years	2,764
After five years through ten years	1,204
After ten years	269
Fixed maturities fair value, subtotal	4,641
Available for sale (AFS) fixed maturities	$ 10,196	$ 10,377
Fair Value Percent, Fiscal Year Maturity [Abstract]
One year or less	4.00%
After one year through five years	27.00%
After five years through ten years	12.00%
After ten years	3.00%
Fixed maturities fair value, subtotal, percent	46.00%
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	$ 3,908
Fair Value, Fiscal Year Maturity [Abstract]
Fixed maturities without single maturity date	$ 3,822
Fair Value Percent, Fiscal Year Maturity [Abstract]
Fixed maturities without single maturity date	37.00%
Mortgage-backed securities
Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Fixed maturities without single maturity date	$ 1,874
Fair Value, Fiscal Year Maturity [Abstract]
Fixed maturities without single maturity date	$ 1,733
Fair Value Percent, Fiscal Year Maturity [Abstract]
Fixed maturities without single maturity date	17.00%