Fair Value (Narrative) (Details) - USD ($)	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Assets, fair value	$ 11,602,000,000	$ 13,525,000,000
Fair Value, Option, Credit Risk, Gains (Losses) on Assets	4,000,000
Level 2
Derivatives, Fair Value [Line Items]
Assets, fair value	10,872,000,000	$ 12,524,000,000
Level 2 \| Fair Value, Nonrecurring \| Collateral dependent loans
Derivatives, Fair Value [Line Items]
Assets, fair value	1,000,000
Gain (losses) from fair value changes	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

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.

+ References

No definition available.

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- Definition

For each line item in the statement of financial position, the amounts of gains and losses from fair value changes included in earnings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-30

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- Definition

This item represents the estimated amount of gains or losses included in earnings during the period attributable to changes in instrument-specific credit risk arising from loans and other receivables held as assets.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-30

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