Summary of Changes in Separate Account Liabilities (Detail) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
Jun. 30, 2024	Dec. 31, 2023
Separate Account, Liability [Line Items]
Beginning balance	$ 4,509	$ 4,417
Premiums and deposits	15	35
Policy charges	(52)	(104)
Surrenders and withdrawals	(201)	(361)
Benefit payments	(118)	(190)
Investment performance	399	716
Net transfers from (to) general account	2	(1)
Other charges	(1)	(3)
Ending balance	4,553	4,509
Cash surrender value	$ 4,550	$ 4,506

Amount of cash outflow to separate account policyholder from benefit payment.

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Amount of separate account liability payable to policyholder upon surrender of contract before maturity.

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Amount of increase (decrease) in separate account liability from performance of investment.

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Amount increase (decrease) in separate account liability from change, 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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Amount of decrease in separate account liability from policy charge.

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Amount of cash inflow to separate account liability from premium and deposit from cash received.

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Amount of decrease in separate account liability from contract redemption and withdrawal of funds.

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Amount of liability for variable contract in which all or portion of contract holder's funds is allocated to specific separate account and supported by assets held in separate account.

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Amount of transfer to (from) liability for policyholder account balance (to) from liability for separate account.

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