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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
--- | ---
Mar. 31, 2023 | Mar. 31, 2022
Accounts Notes And Loans Receivable [Line Items] |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | $ (13) | $ 17
Non Variable Interest Entity [Member] |  |
Accounts Notes And Loans Receivable [Line Items] |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | (13) | 17
Variable Interest Entity [Member] |  |
Accounts Notes And Loans Receivable [Line Items] |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | (3) | (4)
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 | 3 | (8)
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 | (4) | (1)
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 | 7 | 1
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
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) | 8
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 | $ (15) | $ (5)

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