Investments - Net Investment Income (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Net Investment Income [Line Items]
Gross investment income	$ 2,396	$ 2,257	$ 2,393
Investment expenses	(91)	(80)	(80)
Total net investment income	2,305	2,177	2,313
Total fixed maturities
Net Investment Income [Line Items]
Gross investment income	1,895	1,469	1,349
Equity securities
Net Investment Income [Line Items]
Gross investment income	45	57	73
Mortgage loans
Net Investment Income [Line Items]
Gross investment income	235	211	181
Limited partnerships and other alternative investments
Net Investment Income [Line Items]
Gross investment income	212	515	732
Other investments
Net Investment Income [Line Items]
Gross investment income	$ 9	$ 5	$ 58

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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Amount, after 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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