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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, 2025 | Jun. 30, 2024 | Jun. 30, 2025 | Jun. 30, 2024
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | $ (2) | $ (55) | $ (17) | $ (51)
Non Variable Interest Entity [Member] |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | (2) | (55) | (17) | (51)
Variable Interest Entity [Member] |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | 0 | 1 | 0 | (24)
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] | 1 | (60) | 0 | (63)
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 | [2] | 0 | (1) | 0 | (1)
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] | 4 | (4) | 7 | (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] | (3) | 4 | (5) | 6
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] | $ (1) | $ (14) | $ (3) | $ (39)
[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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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 310 -SubTopic 20 -Name Accounting Standards Codification -Section 40 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481628/310-20-40-7 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481990/310-10-45-2 + Details
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