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Derivative Instruments (Narrative) (Detail) $ in Millions | Jun. 30, 2023 USD ($) | Dec. 31, 2022 USD ($)
--- | --- | ---
Derivative [Line Items] |  |
Cash collateral posted to derivative counterparties | $ 0 | $ 0
Securities posted as collateral to derivative counterparties | $ 73 | $ 73
Number of credit support annexes | 1 | 1
Fair value of credit support annexes | $ (1) | $ (1)

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