Loans and Leases - Schedule Of Troubled Debt Restructurings Occurring During The Year (Details) $ in Millions	3 Months Ended
Mar. 31, 2021 USD ($) loan	Mar. 31, 2020 USD ($) loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number \| loan	52	45
Pre-Modification Outstanding Recorded Investment	$ 24	$ 9
Post-Modification Outstanding Recorded Investment	$ 22	$ 7
Consumer \| Consumer Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number \| loan	21	18
Pre-Modification Outstanding Recorded Investment	$ 4	$ 3
Post-Modification Outstanding Recorded Investment	$ 4	$ 3
Consumer \| Credit Card and Other
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number \| loan	13	24
Pre-Modification Outstanding Recorded Investment	$ 0	$ 0
Post-Modification Outstanding Recorded Investment	$ 0	$ 0
C&I \| Commercial \| Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number \| loan	17	3
Pre-Modification Outstanding Recorded Investment	$ 8	$ 6
Post-Modification Outstanding Recorded Investment	$ 8	$ 4
CRE \| Commercial \| Consumer Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number \| loan	1	0
Pre-Modification Outstanding Recorded Investment	$ 12	$ 0
Post-Modification Outstanding Recorded Investment	$ 10	$ 0
HELOC \| Consumer \| Consumer Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number \| loan	12	8
Pre-Modification Outstanding Recorded Investment	$ 2	$ 1
Post-Modification Outstanding Recorded Investment	$ 2	$ 1
R/E Installment Loans \| Consumer \| Consumer Real Estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number \| loan	9	10
Pre-Modification Outstanding Recorded Investment	$ 2	$ 2
Post-Modification Outstanding Recorded Investment	$ 2	$ 2

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

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Amount, after troubled debt restructuring, of modified financing receivable.

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Amount, before troubled debt restructuring, of financing receivable to be modified.

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