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Investment Securities (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
Loan interest receivable | $ 40 | $ 49 |
Securities gains and losses | 0 | $ 0 | $ 0
Carrying value of securities pledged | 15,600 |  |
Federal Reserve Bank Pledges | 7,700 |  |
Pledged to the FHLB as collateral for potential future borrowings - investment securities | 6,600 |  |
Collateral for potential future borrowings | 1,300 |  |
Liabilities secured by pledged collateral | $ 702 |  |

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- Definition Liabilities, primarily public and other deposits of state and local government agencies and derivative instruments, secured by pledged securities. + References No definition available. + Details
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- Definition Amount of restricted investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 860 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (b)(1)(i) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481420/860-30-50-1A Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 954 -SubTopic 210 -Name Accounting Standards Codification -Section 45 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480632/954-210-45-4 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 954 -SubTopic 210 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480602/954-210-50-2 + Details
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