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Fair Value of Financial Instruments (Changes In Level 3 Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Detail) - Fair Value Inputs Level 3 [Member] - 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] |  |  |  |  |  |  |  |
Beginning balance, fair value assets | $ 97 |  | $ 147 |  | $ 96 |  | $ 146 |
Total gains/(losses) included in earnings, assets | $ 4 |  | $ (64) |  | $ 6 |  | $ (68) |
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] | Other Income |  | Other Income |  | Other Income |  | Other Income |
Unrealized gains/(losses) included in OCI, assets | $ 0 | [1] | $ 0 | [2] | $ 0 | [3] | $ 0 | [4]
Purchases, assets | 1 |  | 6 |  | 1 |  | 12 |
Issuances, assets | 0 |  | 0 |  | 0 |  | 0 |
Settlements, assets | (1) |  | (1) |  | (2) |  | (2) |
Sales, assets | 0 |  | (2) |  | 0 |  | (2) |
Transfers into level 3, assets | 0 |  | 0 |  | 0 |  | 0 |
Transfers out of level 3, assets | 0 |  | 0 |  | 0 |  | 0 |
Ending balance, fair value assets | 101 |  | 86 |  | 101 |  | 86 |
Change in unrealized gains/(losses) for the period included in earnings for assets still held, assets | 3 |  | (64) |  | 4 |  | (67) |
Change in unrealized gains/(losses) for the period included in OCI for Assets still held, assets | 0 | [1] | 0 | [2] | 0 | [3] | 0 | [4]
Beginning balance, fair value liabilities | 70 |  | 97 |  | 72 |  | 132 |
Total (gains)/losses included in earnings, liabilities | $ 8 |  | $ 4 |  | $ 12 |  | $ 28 |
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Liability, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration] | Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, before Tax |  | Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, before Tax |  | Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, before Tax |  | Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, before Tax |
Unrealized (gains)/losses included in OCI, liabilities | $ (2) | [5] | $ (3) | [6] | $ (2) | [7] | $ (25) | [8]
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration] | Other Income |  | Other Income |  | Other Income |  | Other Income |
Purchases, liabilities | $ 0 |  | $ 0 |  | $ 0 |  | $ 0 |
Issuances, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Settlements, liabilities | (2) |  | (2) |  | (8) |  | (39) |
Sales, liabilities | 0 |  | (20) |  | 0 |  | (20) |
Transfers into Level 3, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Transfers out of Level 3, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Ending balance, fair value liabilities | 74 |  | 76 |  | 74 |  | 76 |
Change in unrealized gains/(losses) for the period included in earnings for liabilities still held, liabilities | 7 |  | (10) |  | 10 |  | (11) |
Change in Unrealized Gains/ (Losses) for the Period Included in OCI for Liabilities still held | (2) | [5] | 4 | [6] | (2) | [7] | 2 | [8]
Loans receivable - residential [Member] | Variable Interest Entity Primary Beneficiary [Member] |  |  |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |  |  |
Beginning balance, fair value assets | 30 |  | 36 |  | 28 |  | 35 |
Total gains/(losses) included in earnings, assets | 4 |  | (4) |  | 7 |  | (2) |
Unrealized gains/(losses) included in OCI, assets | 0 | [1] | 0 | [2] | 0 | [3] | 0 | [4]
Purchases, assets | 0 |  | 0 |  | 0 |  | 0 |
Issuances, assets | 0 |  | 0 |  | 0 |  | 0 |
Settlements, assets | (1) |  | (1) |  | (2) |  | (2) |
Sales, assets | 0 |  | 0 |  | 0 |  | 0 |
Transfers into level 3, assets | 0 |  | 0 |  | 0 |  | 0 |
Transfers out of level 3, assets | 0 |  | 0 |  | 0 |  | 0 |
Ending balance, fair value assets | 33 |  | 31 |  | 33 |  | 31 |
Change in unrealized gains/(losses) for the period included in earnings for assets still held, assets | 3 |  | (5) |  | 5 |  | (4) |
Change in unrealized gains/(losses) for the period included in OCI for Assets still held, assets | 0 | [1] | 0 | [2] | 0 | [3] | 0 | [4]
Corporate Obligations [Member] |  |  |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |  |  |
Beginning balance, fair value assets | 15 |  | 7 |  | 16 |  | 1 |
Total gains/(losses) included in earnings, assets | 0 |  | (3) |  | (1) |  | (3) |
Unrealized gains/(losses) included in OCI, assets | 0 | [1] | 0 | [2] | 0 | [3] | 0 | [4]
Purchases, assets | 1 |  | 6 |  | 1 |  | 12 |
Issuances, assets | 0 |  | 0 |  | 0 |  | 0 |
Settlements, assets | 0 |  | 0 |  | 0 |  | 0 |
Sales, assets | 0 |  | 0 |  | 0 |  | 0 |
Transfers into level 3, assets | 0 |  | 0 |  | 0 |  | 0 |
Transfers out of level 3, assets | 0 |  | 0 |  | 0 |  | 0 |
Ending balance, fair value assets | 16 | [9],[10] | 10 | [11] | 16 | [9],[10] | 10 | [11]
Change in unrealized gains/(losses) for the period included in earnings for assets still held, assets | 0 |  | (2) |  | (1) |  | 0 |
Change in unrealized gains/(losses) for the period included in OCI for Assets still held, assets | 0 | [1] | 0 | [2] | 0 | [3] | 0 | [4]
Equity investments [Member] |  |  |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |  |  |
Beginning balance, fair value assets | 52 |  | 102 |  | 52 |  | 108 |
Total gains/(losses) included in earnings, assets | 0 |  | (57) |  | 0 |  | (63) |
Unrealized gains/(losses) included in OCI, assets | 0 | [1] | 0 | [2] | 0 | [3] | 0 | [4]
Purchases, assets | 0 |  | 0 |  | 0 |  | 0 |
Issuances, assets | 0 |  | 0 |  | 0 |  | 0 |
Settlements, assets | 0 |  | 0 |  | 0 |  | 0 |
Sales, assets | 0 |  | 0 |  | 0 |  | 0 |
Transfers into level 3, assets | 0 |  | 0 |  | 0 |  | 0 |
Transfers out of level 3, assets | 0 |  | 0 |  | 0 |  | 0 |
Ending balance, fair value assets | 52 |  | 45 |  | 52 |  | 45 |
Change in unrealized gains/(losses) for the period included in earnings for assets still held, assets | 0 |  | (57) |  | 0 |  | (63) |
Change in unrealized gains/(losses) for the period included in OCI for Assets still held, assets | 0 | [1] | 0 | [2] | 0 | [3] | 0 | [4]
Medium Term Notes [Member] |  |  |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |  |  |
Beginning balance, fair value liabilities | 37 |  | 36 |  | 35 |  | 40 |
Total (gains)/losses included in earnings, liabilities | 3 |  | (4) |  | 5 |  | (6) |
Unrealized (gains)/losses included in OCI, liabilities | (2) | [5] | 4 | [6] | (2) | [7] | 2 | [8]
Purchases, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Issuances, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Settlements, liabilities | 0 |  |  |  | 0 |  | 0 |
Sales, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Transfers into Level 3, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Transfers out of Level 3, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Ending balance, fair value liabilities | 38 |  | 36 |  | 38 |  | 36 |
Change in unrealized gains/(losses) for the period included in earnings for liabilities still held, liabilities | 3 |  | (4) |  | 5 |  | (6) |
Change in Unrealized Gains/ (Losses) for the Period Included in OCI for Liabilities still held | (2) | [5] | 4 | [6] | (2) | [7] | 2 | [8]
Variable Interest Entity Notes [Member] | Variable Interest Entity Primary Beneficiary [Member] |  |  |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |  |  |
Beginning balance, fair value liabilities | 27 |  | 46 |  | 31 |  | 78 |
Total (gains)/losses included in earnings, liabilities | 1 |  | 14 |  | 3 |  | 39 |
Unrealized (gains)/losses included in OCI, liabilities | 0 | [5] | (7) | [6] | 0 | [7] | (27) | [8]
Purchases, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Issuances, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Settlements, liabilities | (2) |  | (2) |  | (8) |  | (39) |
Sales, liabilities | 0 |  | (20) |  | 0 |  | (20) |
Transfers into Level 3, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Transfers out of Level 3, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Ending balance, fair value liabilities | 26 |  | 31 |  | 26 |  | 31 |
Change in unrealized gains/(losses) for the period included in earnings for liabilities still held, liabilities | 0 |  | 0 |  | 1 |  | 0 |
Change in Unrealized Gains/ (Losses) for the Period Included in OCI for Liabilities still held | 0 | [5] | 0 | [6] | 0 | [7] | 0 | [8]
Currency Derivatives [Member] | Variable Interest Entity Primary Beneficiary [Member] |  |  |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |  |  |
Beginning balance, fair value liabilities | 6 |  | 15 |  | 6 |  | 14 |
Total (gains)/losses included in earnings, liabilities | 4 |  | (6) |  | 4 |  | (5) |
Unrealized (gains)/losses included in OCI, liabilities | 0 | [5] | 0 | [6] | 0 | [7] | 0 | [8]
Purchases, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Issuances, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Settlements, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Sales, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Transfers into Level 3, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Transfers out of Level 3, liabilities | 0 |  | 0 |  | 0 |  | 0 |
Ending balance, fair value liabilities | 10 |  | 9 |  | 10 |  | 9 |
Change in unrealized gains/(losses) for the period included in earnings for liabilities still held, liabilities | 4 |  | (6) |  | 4 |  | (5) |
Change in Unrealized Gains/ (Losses) for the Period Included in OCI for Liabilities still held | $ 0 | [5] | 0 | [6] | $ 0 | [7] | 0 | [8]
Other Assets [Member] | Variable Interest Entity Primary Beneficiary [Member] |  |  |  |  |  |  |  |
Accounts Notes And Loans Receivable [Line Items] |  |  |  |  |  |  |  |
Beginning balance, fair value assets |  |  | 2 |  |  |  | 2 |
Total gains/(losses) included in earnings, assets |  |  | 0 |  |  |  | 0 |
Unrealized gains/(losses) included in OCI, assets |  |  | 0 | [2] |  |  | 0 | [4]
Purchases, assets |  |  | 0 |  |  |  | 0 |
Issuances, assets |  |  | 0 |  |  |  | 0 |
Settlements, assets |  |  | 0 |  |  |  | 0 |
Sales, assets |  |  | (2) |  |  |  | (2) |
Transfers into level 3, assets |  |  | 0 |  |  |  | 0 |
Transfers out of level 3, assets |  |  | 0 |  |  |  | 0 |
Ending balance, fair value assets |  |  | 0 |  |  |  | 0 |
Change in unrealized gains/(losses) for the period included in earnings for assets still held, assets |  |  | 0 |  |  |  | 0 |
Change in unrealized gains/(losses) for the period included in OCI for Assets still held, assets |  |  | $ 0 | [2] |  |  | $ 0 | [4]
[1] | Reported within the "Unrealized gains (losses) on available-for-sale securities" on the Company's consolidated statements of comprehensive income (loss).
[2] | Reported within the "Unrealized gains (losses) on available-for-sale securities" on the Company's consolidated statements of comprehensive income (loss).
[3] | Reported within the "Unrealized gains (losses) on available-for-sale securities" on the Company's consolidated statements of comprehensive income (loss).
[4] | Reported within the "Unrealized gains (losses) on available-for-sale securities" on the Company's consolidated statements of comprehensive income (loss).
[5] | Reported within the "Instrument-specific credit risk of liabilities measured at fair value" on the Company's consolidated statements of comprehensive income (loss).
[6] | Reported within the "Instrument-specific credit risk of liabilities measured at fair value" on the Company's consolidated statements of comprehensive income (loss).
[7] | Reported within the "Instrument-specific credit risk of liabilities measured at fair value" on the Company's consolidated statements of comprehensive income (loss).
[8] | Reported within the "Instrument-specific credit risk of liabilities measured at fair value" on the Company's consolidated statements of comprehensive income (loss).
[9] | Includes loans carried at fair value of $15 million.
[10] | Includes loans carried at fair value of $15 million.
[11] | Includes loans carried at fair value of $9 million.

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