Fair Value (Fair Value Option - Fair Value and Principal Balances) (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Loans
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value - assets	$ 1,292	$ 1,501
Aggregate unpaid principal balance of assets for which fair value option was elected	1,560	1,804
Fair value option aggregate difference assets	(268)	(303)
Other assets
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value - assets	85	105
Aggregate unpaid principal balance of assets for which fair value option was elected	84	107
Fair value option aggregate difference assets	1	(2)
Other borrowed funds
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value of liabilities for which fair value option was elected	21	30
Aggregate unpaid principal balance, other borrowed funds	22	30
Difference, Other borrowed funds	(1)
Other liabilities
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value of liabilities for which fair value option was elected	121
Difference, Other borrowed funds	121
Accruing loans less than 90 days past due \| Loans
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value - assets	440	487
Aggregate unpaid principal balance of assets for which fair value option was elected	451	498
Fair value option aggregate difference assets	(11)	(11)
Accruing loans 90 days or more past due \| Loans
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value - assets	168	262
Aggregate unpaid principal balance of assets for which fair value option was elected	181	278
Fair value option aggregate difference assets	(13)	(16)
Nonaccrual loans \| Loans
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value - assets	684	752
Aggregate unpaid principal balance of assets for which fair value option was elected	928	1,028
Fair value option aggregate difference assets	(244)	(276)
Residential mortgage loans held for sale \| Loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value - assets	876	1,302
Aggregate unpaid principal balance of assets for which fair value option was elected	892	1,282
Fair value option aggregate difference assets	(16)	20
Residential mortgage loans held for sale \| Accruing loans less than 90 days past due \| Loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value - assets	802	1,249
Aggregate unpaid principal balance of assets for which fair value option was elected	806	1,219
Fair value option aggregate difference assets	(4)	30
Residential mortgage loans held for sale \| Accruing loans 90 days or more past due \| Loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value - assets	11	6
Aggregate unpaid principal balance of assets for which fair value option was elected	11	6
Residential mortgage loans held for sale \| Nonaccrual loans \| Loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value - assets	63	47
Aggregate unpaid principal balance of assets for which fair value option was elected	75	57
Fair value option aggregate difference assets	(12)	(10)
Commercial mortgage loans held for sale \| Accruing loans less than 90 days past due \| Loans held for sale
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair value - assets	106	575
Aggregate unpaid principal balance of assets for which fair value option was elected	135	580
Fair value option aggregate difference assets	$ (29)	$ (5)

Represents the aggregate unpaid principal balance of assets for which the fair value option was elected.

No definition available.

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- Definition

Represents the aggregate unpaid principal balance of liabilities for which the fair value option was elected.

+ References

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- Definition

Represents the fair value of assets for which the fair value option was elected.

+ References

No definition available.

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- Definition

Represents the fair value of liabilities for which the fair value option was elected.

+ References

No definition available.

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- Definition

For assets for which the fair value option has been elected, this item represents the difference between the fair value and the aggregate unpaid principal balance for those assets.

+ References

No definition available.

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For liabilities for which the fair value option has been elected, this item represents the difference between the fair value and the aggregate unpaid principal balance for those assets.

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No definition available.

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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.

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No definition available.

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