Investments - Schedule of Net Investment Income (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Net Investment Income:
Investment income, before expense	$ 823	$ 788	$ 1,748	$ 1,625
Investment expense	(69)	(76)	(140)	(149)
Net investment income	754	712	1,608	1,476
Fixed income securities
Net Investment Income:
Investment income, before expense	602	571	1,210	1,097
Equity securities
Net Investment Income:
Investment income, before expense	17	18	37	33
Mortgage loans
Net Investment Income:
Investment income, before expense	9	9	19	18
Limited partnership interests
Net Investment Income:
Investment income, before expense	74	103	268	302
Short-term investments
Net Investment Income:
Investment income, before expense	97	62	169	129
Other investments
Net Investment Income:
Investment income, before expense	$ 24	$ 25	$ 45	$ 46

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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