Investments - Net Investment Income and Equity in Earnings of Investees (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Net Investment Income
Gross investment income	$ 83	$ 102	$ 250	$ 274
Investment expenses	(1)	(2)	(3)	(4)
Net investment income	82	100	247	270
Fair value gains (losses) on trading securities	9	4	52	42
Equity in Earnings (Losses) of Investees	18	18	47	25
Fair value gains (losses) on trading securities still held	7	4	26	42
Externally managed
Net Investment Income
Gross investment income	52	51	154	156
Loss Mitigation Securities
Net Investment Income
Gross investment income	7	24	21	46
Puerto Rico, New Recovery Bonds
Net Investment Income
Gross investment income	0	1	0	5
Other
Net Investment Income
Gross investment income	3	5	9	12
Short-term investments
Net Investment Income
Gross investment income	21	21	66	53
Other
Net Investment Income
Gross investment income	0	0	0	2
Sound Point
Net Investment Income
Equity in Earnings (Losses) of Investees	4	0	5	0
Funds
Net Investment Income
Equity in Earnings (Losses) of Investees	8	12	27	12
Equity method investments
Net Investment Income
Equity in Earnings (Losses) of Investees	$ 6	$ 6	$ 15	$ 13

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 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 of expenses related to the generation of investment income.

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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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