Investments - Net Investment Income and Equity in Earnings of Investees (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Net Investment Income
Gross investment income	$ 102	$ 68	$ 274	$ 195
Investment expenses	(2)	(1)	(4)	(4)
Net investment income	100	67	270	191
Fair value gains (losses) on trading securities	4	(8)	42	(30)
Equity in Earnings (Losses) of Investees	18	(20)	25	(31)
Fair value loss on trading securities still held	4	2	42	18
Externally managed
Net Investment Income
Gross investment income	51	50	156	150
Loss Mitigation Securities
Net Investment Income
Gross investment income	24	9	46	24
Puerto Rico, New Recovery Bonds
Net Investment Income
Gross investment income	1	1	5	5
Other
Net Investment Income
Gross investment income	5	4	12	11
Short-term investments
Net Investment Income
Gross investment income	21	4	53	5
Other
Net Investment Income
Gross investment income	$ 0	$ 0	$ 2	$ 0

Amount of unrealized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in net income (trading).

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

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Amount of income (loss) for proportionate share of equity method investee's income (loss).

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Represents the total of interest and dividend income, including any amortization and accretion (as applicable) of discounts and premiums, earned from (1) loans and leases whether held-for-sale or held-in-portfolio; (2) investment securities; (3) federal funds sold; (4) securities purchased under agreements to resell; (5) investments in banker's acceptances, commercial paper, or certificates of deposit; (6) dividend income; or (7) other investments not otherwise specified herein.

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Amount, after investment expense, of income earned from investments in securities and real estate. Includes, but is not limited to, real estate investment, policy loans, dividends, and interest. Excludes realized gain (loss) on investments.

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