Credit Quality - Summary of the Nonperforming Loans and Leases by Class (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Financing Receivable, Modifications [Line Items]
Nonaccrual portfolio loans and leases	$ 482	$ 348
OREO and other repossessed property	37	47
Nonperforming portfolio assets	519	395
Commercial Portfolio Segment
Financing Receivable, Modifications [Line Items]
Nonaccrual portfolio loans and leases	349	228
Commercial Portfolio Segment \| Commercial and Industrial Loans
Financing Receivable, Modifications [Line Items]
Nonaccrual portfolio loans and leases	293	193
Commercial Portfolio Segment \| Commercial Mortgage Loans, Owner-occupied
Financing Receivable, Modifications [Line Items]
Nonaccrual portfolio loans and leases	24	11
Commercial Portfolio Segment \| Commercial Mortgage Loans, Nonowner-Occupied
Financing Receivable, Modifications [Line Items]
Nonaccrual portfolio loans and leases	2	2
Commercial Portfolio Segment \| Commercial Leases
Financing Receivable, Modifications [Line Items]
Nonaccrual portfolio loans and leases	30	22
Residential Mortgage Loans
Financing Receivable, Modifications [Line Items]
Nonaccrual portfolio loans and leases	22	22
Consumer Portfolio Segment
Financing Receivable, Modifications [Line Items]
Nonaccrual portfolio loans and leases	111	98
Consumer Portfolio Segment \| Home Equity
Financing Receivable, Modifications [Line Items]
Nonaccrual portfolio loans and leases	80	69
Consumer Portfolio Segment \| Indirect secured consumer loans
Financing Receivable, Modifications [Line Items]
Nonaccrual portfolio loans and leases	2	1
Consumer Portfolio Segment \| Credit Card
Financing Receivable, Modifications [Line Items]
Nonaccrual portfolio loans and leases	27	27
Consumer Portfolio Segment \| Other Consumer Loans
Financing Receivable, Modifications [Line Items]
Nonperforming portfolio assets	$ 2	$ 1

Reflects the carrying amount of loans deemed to be questionable as to collection on which no interest is continuing to be recognized and the carrying amount of other real estate and foreclosed assets, excluding government guaranteed loans.

No definition available.

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+ References

No definition available.

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- Definition

Reflects the carrying amount of loans deemed to be questionable as to collection on which no interest is continuing to be recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5111-111524

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+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(4))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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