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Fair Value Measurements - Carrying Amounts and Estimated Fair Value for Financial Instrument Assets (Liabilities) (Detail) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Financial assets: |  |
Interest-bearing deposits at banks | $ 18,873 | $ 28,069
Investment securities held to maturity | 34,051 | 26,897
Net loans and leases | 133,397 | 131,939
Financial liabilities: |  |
Long-term borrowings | 12,605 | 8,201
Level 1 |  |
Financial assets: |  |
Cash and cash equivalents | 1,749 | 1,668
Interest-bearing deposits at banks | 0 | 0
Investment securities held to maturity | 0 | 0
Net loans and leases | 0 | 0
Financial liabilities: |  |
Time deposits | 0 | 0
Short-term borrowings | 0 | 0
Long-term borrowings | 0 | 0
Level 2 |  |
Financial assets: |  |
Cash and cash equivalents | 160 | 63
Interest-bearing deposits at banks | 18,873 | 28,069
Investment securities held to maturity | 12,909 | 14,262
Net loans and leases | 6,806 | 7,240
Financial liabilities: |  |
Time deposits | 14,463 | 20,715
Short-term borrowings | 1,060 | 5,316
Long-term borrowings | 12,754 | 8,107
Level 3 |  |
Financial assets: |  |
Cash and cash equivalents | 0 | 0
Interest-bearing deposits at banks | 0 | 0
Investment securities held to maturity | 46 | 46
Net loans and leases | 124,528 | 121,898
Financial liabilities: |  |
Time deposits | 0 | 0
Short-term borrowings | 0 | 0
Long-term borrowings | 0 | 0
Carrying Amount |  |
Financial assets: |  |
Cash and cash equivalents | 1,909 | 1,731
Interest-bearing deposits at banks | 18,873 | 28,069
Investment securities held to maturity | 14,195 | 15,330
Net loans and leases | 133,397 | 131,939
Financial liabilities: |  |
Time deposits | 14,476 | 20,759
Short-term borrowings | 1,060 | 5,316
Long-term borrowings | 12,605 | 8,201
Estimated Fair Value |  |
Financial assets: |  |
Cash and cash equivalents | 1,909 | 1,731
Interest-bearing deposits at banks | 18,873 | 28,069
Investment securities held to maturity | 12,955 | 14,308
Net loans and leases | 131,334 | 129,138
Financial liabilities: |  |
Time deposits | 14,463 | 20,715
Short-term borrowings | 1,060 | 5,316
Long-term borrowings | $ 12,754 | $ 8,107

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