Fair Value Measurements - Fair Value Recurring Basis, Unobservable Input (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Assets
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net realized gains (losses)	Net realized gains (losses)
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring
Assets
Beginning balance	$ 2,708	$ 1,805
Total realized/unrealized gains (losses), Included in net income	(14)	50
Total realized/unrealized gains (losses), Included in OCI	(205)	(38)
Purchases	1,215	2,145
Settlements	(591)	(570)
Sales	(47)	(72)
Transfers into Level 3	48	177
Transfers out of Level 3	(631)	(789)
Ending balance	2,483	2,708
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Equity Securities [Member]
Assets
Beginning balance	64	70
Total realized/unrealized gains (losses), Included in net income	11	42
Total realized/unrealized gains (losses), Included in OCI	0	0
Purchases	2	6
Settlements	(16)	(53)
Sales	0	(1)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Ending balance	61	64
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Short-term Investments [Member]
Assets
Beginning balance	80	30
Total realized/unrealized gains (losses), Included in net income	0	0
Total realized/unrealized gains (losses), Included in OCI	0	0
Purchases	284	98
Settlements	(121)	(48)
Sales	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	(50)	0
Ending balance	193	80
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Securities available-for-sale and other \| Total fixed maturities
Assets
Beginning balance	2,404	1,705
Total realized/unrealized gains (losses), Included in net income	(1)	14
Total realized/unrealized gains (losses), Included in OCI	(205)	(38)
Purchases	874	1,881
Settlements	(441)	(475)
Sales	(47)	(71)
Transfers into Level 3	48	177
Transfers out of Level 3	(581)	(789)
Ending balance	2,051	2,404
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Securities available-for-sale and other \| ABS \| Total fixed maturities
Assets
Beginning balance	0	0
Total realized/unrealized gains (losses), Included in net income	0	0
Total realized/unrealized gains (losses), Included in OCI	0	0
Purchases	49	42
Settlements	0	0
Sales	0	(3)
Transfers into Level 3	0	0
Transfers out of Level 3	(19)	(39)
Ending balance	30	0
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Securities available-for-sale and other \| CLO \| Total fixed maturities
Assets
Beginning balance	257	360
Total realized/unrealized gains (losses), Included in net income	0	0
Total realized/unrealized gains (losses), Included in OCI	(2)	(1)
Purchases	113	471
Settlements	(62)	(124)
Sales	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	(191)	(449)
Ending balance	115	257
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Securities available-for-sale and other \| CMBS \| Total fixed maturities
Assets
Beginning balance	196	77
Total realized/unrealized gains (losses), Included in net income	0	0
Total realized/unrealized gains (losses), Included in OCI	(15)	1
Purchases	51	166
Settlements	(10)	(4)
Sales	0	(1)
Transfers into Level 3	0	5
Transfers out of Level 3	0	(48)
Ending balance	222	196
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Securities available-for-sale and other \| Corporate \| Total fixed maturities
Assets
Beginning balance	1,618	881
Total realized/unrealized gains (losses), Included in net income	0	14
Total realized/unrealized gains (losses), Included in OCI	(174)	(34)
Purchases	524	828
Settlements	(274)	(154)
Sales	(40)	(47)
Transfers into Level 3	45	172
Transfers out of Level 3	(110)	(42)
Ending balance	1,589	1,618
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Securities available-for-sale and other \| Foreign government/government agencies \| Total fixed maturities
Assets
Beginning balance	5	6
Total realized/unrealized gains (losses), Included in net income	(1)	0
Total realized/unrealized gains (losses), Included in OCI	0	0
Purchases	0	5
Settlements	0	0
Sales	(7)	(6)
Transfers into Level 3	3	0
Transfers out of Level 3	0	0
Ending balance	0	5
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Securities available-for-sale and other \| Residential mortgage-backed securities ("RMBS") \| Total fixed maturities
Assets
Beginning balance	328	381
Total realized/unrealized gains (losses), Included in net income	0	0
Total realized/unrealized gains (losses), Included in OCI	(14)	(4)
Purchases	137	369
Settlements	(95)	(193)
Sales	0	(14)
Transfers into Level 3	0	0
Transfers out of Level 3	(261)	(211)
Ending balance	95	328
Significant Unobservable Inputs (Level 3) \| Fair Value, Measurements, Recurring \| Fair Value Option, Other Eligible Items \| CLO \| Total fixed maturities
Assets
Beginning balance	160	0
Total realized/unrealized gains (losses), Included in net income	(24)	(6)
Total realized/unrealized gains (losses), Included in OCI	0	0
Purchases	55	160
Settlements	(13)	6
Sales	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Ending balance	$ 178	$ 160

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

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Amount of gain (loss) recognized in other comprehensive income (OCI) from asset measured at fair value on recurring basis using unobservable input (level 3).

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Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

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Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Indicates line item in statement in which net income is reported that includes gain (loss) from asset measured at fair value using unobservable input (level 3).

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