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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 | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Accounts Notes And Loans Receivable [Line Items] |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | $ 45 | $ 40 | $ (80)
Non Variable Interest Entity [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | 45 | 40 | (80)
Variable Interest Entity [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | (14) | (8) | 108
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 | (17) | 3 | 2
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 | (5) | 4 | 4
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 | 10 | 32 | 0
Loan Repurchase Commitments [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 | (4) | 118
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 | 9 | 0 | (4)
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 | 24 | 17 | (15)
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 | $ (20) | $ (50) | $ (12)

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