Investments - Scheduled maturities of available for sale fixed maturities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Fair Value, Fiscal Year Maturity [Abstract]
Available for sale (AFS) fixed maturities	$ 10,398	$ 10,377
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
Fixed maturities
Amortized Cost Basis, Fiscal Year Maturity [Abstract]
One year or less	$ 552
After one year through five years	2,738
After five years through ten years	1,296
After ten years	250
Fixed maturities amortized cost, Subtotal	4,836
Amortized cost	10,653
Fair Value, Fiscal Year Maturity [Abstract]
One year or less	540
After one year through five years	2,704
After five years through ten years	1,286
After ten years	235
Fixed maturities fair value, Subtotal	4,765
Available for sale (AFS) fixed maturities	$ 10,398	$ 10,377
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	12.00%
After ten years	2.00%
Fixed maturities fair value, Subtotal, Percent	45.00%
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	$ 3,645
Fair Value, Fiscal Year Maturity [Abstract]
Fixed maturities without a single maturity date	$ 3,593
Fair Value Percent, Fiscal Year Maturity [Abstract]
Fixed maturities without a single maturity date, percent of fair value	35.00%
Mortgage-backed securities
Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Fixed maturities without a single maturity date	$ 2,172
Fair Value, Fiscal Year Maturity [Abstract]
Fixed maturities without a single maturity date	$ 2,040
Fair Value Percent, Fiscal Year Maturity [Abstract]
Fixed maturities without a single maturity date, percent of fair value	20.00%