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Fair Value Of Financial Instruments (Gains And Losses On Fair Value Option Included In The Company's Consolidated Statements Of Operations) (Detail) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2023 | Jun. 30, 2022 | Jun. 30, 2023 | Jun. 30, 2022
Accounts Notes And Loans Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | $ 11 | $ 9 | $ (1) | $ 26
Non Variable Interest Entity [Member] |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | 11 | 9 | (1) | 26
Variable Interest Entity [Member] |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | (21) | 24 | (24) | 20
Investments Carried At Fair Value [Member] |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | 0 | (26) | 3 | (34)
Fixed Maturity Securities Held At Fair Value - VIE [Member] | Variable Interest Entity [Member] |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | 0 | (2) | (4) | (3)
Loans Receivable and Other Instruments at Fair Value [Member] | Variable Interest Entity [Member] | Residential Mortgage Loans [Member] |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | (11) | (6) | (3) | (5)
Other Assets [Member] | Variable Interest Entity [Member] |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | 2 | 1 | 3 | 2
Medium Term Notes [Member] | Non Variable Interest Entity [Member] |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | 3 | 13 | 0 | 22
Variable Interest Entity Notes [Member] | Variable Interest Entity [Member] |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | $ (17) | $ 28 | $ (33) | $ 23

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