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Variable Interest Entities (VIEs) (Narrative) (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023	Sep. 30, 2022
Variable Interest Entity [Line Items]
Unfunded commitments to fund tax credit entities	$ 219,000,000
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	482,000,000	482,000,000
Other Tax Credit Entities
Variable Interest Entity [Line Items]
Exposure to loss as a result of involvement with VIEs	$ 27,000,000	$ 27,000,000

X

- Definition

The amount of expense between the reporting entity and the Variable Interest Entity (VIE).

+ References

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- Definition

The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE).

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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.

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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.

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