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Investment Information - 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:
Gross investment income		$ 429	$ 386	$ 836	$ 736
Investment expenses		(24)	(22)	(53)	(45)
Net investment income		405	364	783	691
Fixed maturities
Net investment income:
Gross investment income		360	306	702	586
Short-term investments
Net investment income:
Gross investment income		24	35	50	64
Equity securities
Net investment income:
Gross investment income		10	10	21	18
Other
Net investment income:
Gross investment income	[1]	$ 35	$ 35	$ 63	$ 68
[1] Amounts include dividends and other distributions on investment funds, term loan investments, funds held balances, cash balances and other items.

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