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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, 2025 | Mar. 31, 2024
Accounts Notes And Loans Receivable [Line Items] |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | $ (15) | $ 4
Non Variable Interest Entity [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | (15) | 4
Variable Interest Entity [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | 0 | (25)
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 | [1] | (2) | (4)
Loans Receivable at Fair Value [Member] | Residential Mortgage Loans [Member] |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | [2] | 2 | 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 | [1] | (2) | 2
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 | [2] | $ (2) | $ (25)
[1] | Reported within "Net gains (losses) on financial instruments at fair value and foreign exchange" on the Company's consolidated statements of operations.
[2] | Reported within "Net gains (losses) on financial instruments at fair value and foreign exchange-VIE" and/or "Other net realized gains (losses)-VIE" on the Company's consolidated statements of operations.

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