Investments - Net Investment Income (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Net Investment Income [Line Items]
Investment income, operating	$ 615	$ 388	$ 1,205	$ 839
Investment expenses	(23)	(22)	(44)	(41)
Net investment income	592	366	1,161	798
Net investment income (loss) recognized due to the change in fair value of equity and trading portfolio securities held as of June 30, 2023 and 2022	15	(95)	20	(120)
Fixed maturity securities
Net Investment Income [Line Items]
Investment income, operating	482	441	952	870
Limited partnership investments
Net Investment Income [Line Items]
Gain (losses) on investments, before investment expenses	55	7	82	27
Short term investments
Net Investment Income [Line Items]
Investment income, operating	14		30
Equity securities
Net Investment Income [Line Items]
Gain (losses) on investments, before investment expenses	21	(11)	33	(9)
Income (loss) from trading portfolio
Net Investment Income [Line Items]
Gain (losses) on investments, before investment expenses	14	(62)	59	(77)
Other
Net Investment Income [Line Items]
Investment income, operating	$ 29	$ 13	$ 49	$ 28

Amount, before investment expenses, of gains (losses) on investments.

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Trading Securities, Change in Unrealized Holding Gain (Loss), Net Investment Income Recognized

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- Definition

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 of expenses related to the generation of investment income.

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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.

+ References

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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