Investments (Net investment income) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Net Investment Income [Line Items]
Gross investment income	$ 2,648	$ 2,582	$ 2,343
Investment expense	(91)	(85)	(79)
Net investment income	2,557	2,497	2,264
Fixed maturity securities
Net Investment Income [Line Items]
Gross investment income	2,143	2,051	1,941
Equity securities
Net Investment Income [Line Items]
Gross investment income	60	82	63
Limited partnership investments
Net Investment Income [Line Items]
Gross investment income	276	271
Gross investment loss			174
Mortgage loans
Net Investment Income [Line Items]
Gross investment income	64	58	58
Short-term investments
Net Investment Income [Line Items]
Gross investment income	73	87	75
Trading portfolio
Net Investment Income [Line Items]
Gross investment income	5	2	4
Other
Net Investment Income [Line Items]
Gross investment income	27	31	28
Common Stock
Net Investment Income [Line Items]
Equity securities, FV-NI, gain (loss)	24	28	11
Non-redeemable preferred stock
Net Investment Income [Line Items]
Equity securities, FV-NI, gain (loss)	$ 7	$ 19	$ 14

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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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