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Investments - Available for sale fixed maturities (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Fixed maturies, available for sale, amortized cost	$ 10,736	$ 10,193
Fixed maturities, available for sale, allowance for expected credit losses	11	9	$ 12	$ 0
Available for sale (AFS) fixed maturities	10,095	10,357
Total fixed maturities
Debt Securities, Available-for-sale [Line Items]
Fixed maturies, available for sale, amortized cost	10,736	10,193
Fixed maturities, available for sale, allowance for expected credit losses	11	9
Gross unrealized gains on available for sale fixed maturities	39	201
Gross unrealized losses on available for sale fixed maturities	(669)	(28)
Available for sale (AFS) fixed maturities	10,095	10,357
Total fixed maturities \| Debt Securities
Debt Securities, Available-for-sale [Line Items]
Net unrealized gain (loss) on available for sale fixed maturities	(630)	173
U.S. Government and government agencies
Debt Securities, Available-for-sale [Line Items]
Fixed maturies, available for sale, amortized cost	233	216
Fixed maturities, available for sale, allowance for expected credit losses	0	0
Gross unrealized gains on available for sale fixed maturities	0	2
Gross unrealized losses on available for sale fixed maturities	(14)	(2)
Available for sale (AFS) fixed maturities	219	216
U.S. Government and government agencies \| Debt Securities
Debt Securities, Available-for-sale [Line Items]
Net unrealized gain (loss) on available for sale fixed maturities	(14)	0
States, municipalities and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Fixed maturies, available for sale, amortized cost	1,234	1,758
Fixed maturities, available for sale, allowance for expected credit losses	0	0
Gross unrealized gains on available for sale fixed maturities	3	74
Gross unrealized losses on available for sale fixed maturities	(51)	0
Available for sale (AFS) fixed maturities	1,186	1,832
States, municipalities and political subdivisions \| Debt Securities
Debt Securities, Available-for-sale [Line Items]
Net unrealized gain (loss) on available for sale fixed maturities	(48)	74
Foreign government
Debt Securities, Available-for-sale [Line Items]
Fixed maturies, available for sale, amortized cost	240	248
Fixed maturities, available for sale, allowance for expected credit losses	0	0
Gross unrealized gains on available for sale fixed maturities	0	0
Gross unrealized losses on available for sale fixed maturities	(14)	(2)
Available for sale (AFS) fixed maturities	226	246
Foreign government \| Debt Securities
Debt Securities, Available-for-sale [Line Items]
Net unrealized gain (loss) on available for sale fixed maturities	(14)	(2)
Residential MBS
Debt Securities, Available-for-sale [Line Items]
Fixed maturies, available for sale, amortized cost	1,757	915
Fixed maturities, available for sale, allowance for expected credit losses	2	0
Gross unrealized gains on available for sale fixed maturities	23	48
Gross unrealized losses on available for sale fixed maturities	(180)	(3)
Available for sale (AFS) fixed maturities	1,598	960
Residential MBS \| Debt Securities
Debt Securities, Available-for-sale [Line Items]
Net unrealized gain (loss) on available for sale fixed maturities	(157)	45
Commercial MBS
Debt Securities, Available-for-sale [Line Items]
Fixed maturies, available for sale, amortized cost	88	102
Fixed maturities, available for sale, allowance for expected credit losses	0	0
Gross unrealized gains on available for sale fixed maturities	0	2
Gross unrealized losses on available for sale fixed maturities	(3)	0
Available for sale (AFS) fixed maturities	85	104
Commercial MBS \| Debt Securities
Debt Securities, Available-for-sale [Line Items]
Net unrealized gain (loss) on available for sale fixed maturities	(3)	2
Collateralized loan obligations
Debt Securities, Available-for-sale [Line Items]
Fixed maturies, available for sale, amortized cost	1,988	1,643
Fixed maturities, available for sale, allowance for expected credit losses	1	1
Gross unrealized gains on available for sale fixed maturities	1	3
Gross unrealized losses on available for sale fixed maturities	(67)	(2)
Available for sale (AFS) fixed maturities	1,921	1,643
Collateralized loan obligations \| Debt Securities
Debt Securities, Available-for-sale [Line Items]
Net unrealized gain (loss) on available for sale fixed maturities	(66)	1
Other asset-backed securities
Debt Securities, Available-for-sale [Line Items]
Fixed maturies, available for sale, amortized cost	2,435	2,677
Fixed maturities, available for sale, allowance for expected credit losses	7	7
Gross unrealized gains on available for sale fixed maturities	1	17
Gross unrealized losses on available for sale fixed maturities	(184)	(11)
Available for sale (AFS) fixed maturities	2,245	2,676
Other asset-backed securities \| Debt Securities
Debt Securities, Available-for-sale [Line Items]
Net unrealized gain (loss) on available for sale fixed maturities	(183)	6
Corporate and other
Debt Securities, Available-for-sale [Line Items]
Fixed maturies, available for sale, amortized cost	2,761	2,634
Fixed maturities, available for sale, allowance for expected credit losses	1	1	$ 2	$ 0
Gross unrealized gains on available for sale fixed maturities	11	55
Gross unrealized losses on available for sale fixed maturities	(156)	(8)
Available for sale (AFS) fixed maturities	2,615	2,680
Corporate and other \| Debt Securities
Debt Securities, Available-for-sale [Line Items]
Net unrealized gain (loss) on available for sale fixed maturities	$ (145)	$ 47