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Variable Interest Entities (VIEs) (Narrative) (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2023 | Dec. 31, 2022
Variable Interest Entity [Line Items] |  |
Unfunded commitments to fund tax credit entities | $ 231 |
Amount of financial or other support not contractually required provided by the Corporation to VIEs | 0 | $ 0
Low Income Housing Tax Credit Entities |  |
Variable Interest Entity [Line Items] |  |
Exposure to loss as a result of involvement with VIEs | 500 |
Other Tax Credit Entities |  |
Variable Interest Entity [Line Items] |  |
Exposure to loss as a result of involvement with VIEs | $ 29 |

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- Definition The amount of expense between the reporting entity and the Variable Interest Entity (VIE). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph d -Publisher FASB -URI https://asc.fasb.org//1943274/2147481203/810-10-50-6 + Details
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- Definition The amount of financial or other support the reporting entity has provided (explicitly or implicitly) to the Variable Interest Entity (VIE) that it was not previously contractually required to provide or that the reporting entity intends to provide, including, for example, situations in which the reporting entity assisted the VIE in obtaining another type of support. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 5A -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481203/810-10-50-5A + Details
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