Net Investment Income (Schedule of Net Investment Income) (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Total investment income	$ 343	$ 218	$ 225
Deposits and other investments	135	47	69
Deferred compensation plan assets	(25)	19	13
Equity in earnings of affiliates, net	11	7	6
Other	7	1	0
Investment expenses	(3)	(3)	(4)
Net investment income	340	215	221
Debt Securities
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Total investment income	206	133	126
Equity Securities
Schedule Of Investment Income Reported Amounts By Category [Line Items]
Total investment income	$ 9	$ 11	$ 11

Income (loss) from deferred compensation plan assets.

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Investment income interest on other investments.

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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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Amount of income (loss) for proportionate share of equity method investee's income (loss).

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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.

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Amount, after discount, accretion and premium amortization, of interest income and dividend income classified as other.

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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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