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	$ 4,917	$ 4,313	$ 4,962
Less: Investment expenses	357	249	147
Net investment income	4,560	4,064	4,815
Fixed maturity securities
Net Investment Income [Line Items]
Gross investment income	3,481	3,044	2,794
Equity securities
Net Investment Income [Line Items]
Gross investment income	2	2	5
Mortgage loans
Net Investment Income [Line Items]
Gross investment income	957	840	686
Policy loans
Net Investment Income [Line Items]
Gross investment income	45	42	41
Limited partnerships and LLCs
Net Investment Income [Line Items]
Gross investment income	167	263	1,391
Cash, cash equivalents and short-term investments
Net Investment Income [Line Items]
Gross investment income	181	56	3
Other
Net Investment Income [Line Items]
Gross investment income	$ 84	$ 66	$ 42

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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