Investments (Details) - Net Investment Income - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Net investment income
Gross investment income	$ 3,637	$ 2,966	$ 2,605
Investment expenses	47	44	43
Net investment income	3,590	2,922	2,562
Fixed maturities [Member]
Net investment income
Gross investment income	2,948	2,472	2,113
Equity securities [Member]
Net investment income
Gross investment income	21	18	17
Short-term securities [Member]
Net investment income
Gross investment income	280	241	73
Real estate [Member]
Net investment income
Gross investment income	70	64	66
Other investments [Member]
Net investment income
Gross investment income	$ 318	$ 171	$ 336

Amount, before 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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