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Fair Value of Financial Instruments (Realized And Unrealized Gains And Losses Included In Earnings Pertaining To Level 3 Assets And Liabilities) (Detail) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended
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Jun. 30, 2025 | Jun. 30, 2024 | Jun. 30, 2025 | Jun. 30, 2024
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | $ (2) | $ (55) | $ (17) | $ (51)
Variable Interest Entity, Primary Beneficiary [Member] |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | 0 | 1 | 0 | (24)
Fair Value Inputs Level 3 [Member] | Total Gains (Losses) Included in Earnings [Member] |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | (3) | (56) | (6) | (60)
Total revenues |  | $ (4) | $ (68) | $ (6) | $ (96)
Fair Value, Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] |  | Realized Investment Gains (Losses) | Realized Investment Gains (Losses) | Realized Investment Gains (Losses) | Realized Investment Gains (Losses)
Fair Value Inputs Level 3 [Member] | Change in Unrealized Gains (Losses) for the Period Included in Earnings for Assets and Liabilities still held [Member] |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange |  | $ (3) | $ (55) | $ (6) | $ (57)
Total revenues |  | (4) | (54) | (6) | (56)
Fair Value Inputs Level 3 [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Total Gains (Losses) Included in Earnings [Member] |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | [1] | (1) | (12) | 0 | (36)
Fair Value Inputs Level 3 [Member] | Variable Interest Entity, Primary Beneficiary [Member] | Change in Unrealized Gains (Losses) for the Period Included in Earnings for Assets and Liabilities still held [Member] |  |  |  |  |
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] |  |  |  |  |
Net gains (losses) on financial instruments at fair value and foreign exchange | [1] | $ (1) | $ 1 | $ 0 | $ 1
[1] | Reported within "Net gains (losses) on financial instruments at fair value and foreign exchange-VIE" and "Other net realized gains (losses)-VIE" on the Company's consolidated statements of operations.

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- Definition Change in the fair value of and realized gains and losses on sale of financial instruments and foreign exchange included in earnings. + References No definition available. + Details
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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/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 100 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-100 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-3 + Details
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