Investments - Schedule of Net Investment Income (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Net Investment Income:
Investment income, before expense	$ 1,020	$ 863	$ 2,768	$ 2,488
Investment expense	(71)	(80)	(211)	(229)
Net investment income	949	783	2,557	2,259
Fixed income securities
Net Investment Income:
Investment income, before expense	634	587	1,844	1,684
Equity securities
Net Investment Income:
Investment income, before expense	19	17	56	50
Mortgage loans
Net Investment Income:
Investment income, before expense	11	9	30	27
Limited partnership interests
Net Investment Income:
Investment income, before expense	226	138	494	440
Short-term investments
Net Investment Income:
Investment income, before expense	104	87	273	216
Other investments
Net Investment Income:
Investment income, before expense	$ 26	$ 25	$ 71	$ 71

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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