Investments - Schedule of Net Investment Income (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:
Investment income, before expense	$ 863	$ 771	$ 2,488	$ 2,102
Investment expense	(80)	(82)	(229)	(228)
Net investment income	783	689	2,259	1,874
Fixed income securities
Net Investment Income:
Investment income, before expense	587	457	1,684	1,269
Equity securities
Net Investment Income:
Investment income, before expense	17	15	50	47
Mortgage loans
Net Investment Income:
Investment income, before expense	9	9	27	25
Limited partnership interests
Net Investment Income:
Investment income, before expense	138	190	440	446
Short-term investments
Net Investment Income:
Investment income, before expense	87	59	216	194
Other investments
Net Investment Income:
Investment income, before expense	$ 25	$ 41	$ 71	$ 121

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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