Credit Quality - Recorded Investment in Impaired Loans and Related Allowance by Class (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Impaired Financing Receivable Unpaid Principal Balance
Impaired Financing Receivable With Related Allowance Unpaid Principal Balance	$ 948	$ 846
Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance	599	536
Unpaid Principal Balance	1,547	1,382
Impaired Financing Receivable Recorded Investment Abstract
Impaired Financing Receivable With Related Allowance Recorded Investment	883	787
Impaired Financing Receivable With No Related Allowance Recorded Investment	557	504
Recorded investment	1,440	1,291
Allowance	157	141
Commercial Portfolio Segment \| Commercial and Industrial Loans
Impaired Financing Receivable Unpaid Principal Balance
Impaired Financing Receivable With Related Allowance Unpaid Principal Balance	260	156
Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance	180	137
Impaired Financing Receivable Recorded Investment Abstract
Impaired Financing Receivable With Related Allowance Recorded Investment	203	107
Impaired Financing Receivable With No Related Allowance Recorded Investment	157	125
Allowance	47	34
Commercial Portfolio Segment \| Commercial Mortgage Loans, Owner-occupied
Impaired Financing Receivable Unpaid Principal Balance
Impaired Financing Receivable With Related Allowance Unpaid Principal Balance	4	2
Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance	24	9
Impaired Financing Receivable Recorded Investment Abstract
Impaired Financing Receivable With Related Allowance Recorded Investment	4	2
Impaired Financing Receivable With No Related Allowance Recorded Investment	23	9
Allowance	0	1
Commercial Portfolio Segment \| Commercial Mortgage Loans, Nonowner-Occupied
Impaired Financing Receivable Unpaid Principal Balance
Impaired Financing Receivable With Related Allowance Unpaid Principal Balance	2	2
Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance	3	11
Impaired Financing Receivable Recorded Investment Abstract
Impaired Financing Receivable With Related Allowance Recorded Investment	1	1
Impaired Financing Receivable With No Related Allowance Recorded Investment	3	11
Allowance	0	0
Commercial Portfolio Segment \| Commercial Leases
Impaired Financing Receivable Unpaid Principal Balance
Impaired Financing Receivable With Related Allowance Unpaid Principal Balance	37	23
Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance	1
Impaired Financing Receivable Recorded Investment Abstract
Impaired Financing Receivable With Related Allowance Recorded Investment	34	22
Impaired Financing Receivable With No Related Allowance Recorded Investment	1
Allowance	16	7
Residential Mortgage Loans
Impaired Financing Receivable Unpaid Principal Balance
Impaired Financing Receivable With Related Allowance Unpaid Principal Balance	453	465
Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance	318	292
Impaired Financing Receivable Recorded Investment Abstract
Impaired Financing Receivable With Related Allowance Recorded Investment	451	462
Impaired Financing Receivable With No Related Allowance Recorded Investment	301	274
Allowance	59	61
Consumer Portfolio Segment \| Home Equity
Impaired Financing Receivable Unpaid Principal Balance
Impaired Financing Receivable With Related Allowance Unpaid Principal Balance	143	146
Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance	72	85
Impaired Financing Receivable Recorded Investment Abstract
Impaired Financing Receivable With Related Allowance Recorded Investment	143	145
Impaired Financing Receivable With No Related Allowance Recorded Investment	71	83
Allowance	22	22
Consumer Portfolio Segment \| Indirect secured consumer loans
Impaired Financing Receivable Unpaid Principal Balance
Impaired Financing Receivable With Related Allowance Unpaid Principal Balance	4	5
Impaired Financing Receivable With No Related Allowance Unpaid Principal Balance	1	2
Impaired Financing Receivable Recorded Investment Abstract
Impaired Financing Receivable With Related Allowance Recorded Investment	4	4
Impaired Financing Receivable With No Related Allowance Recorded Investment	1	2
Allowance	1	1
Consumer Portfolio Segment \| Credit Card
Impaired Financing Receivable Unpaid Principal Balance
Impaired Financing Receivable With Related Allowance Unpaid Principal Balance	45	47
Impaired Financing Receivable Recorded Investment Abstract
Impaired Financing Receivable With Related Allowance Recorded Investment	43	44
Allowance	$ 12	$ 15

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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-Name Accounting Standards Codification
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