Loans - 90+ Day Delinquent Loans Accruing Interest and Nonperforming Loans (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days Past Due and Accruing	$ 2,110	$ 2,233
Nonperforming Loans	$ 753	$ 813
Percentage, 90 Days Past Due and Accruing	0.90%	0.90%
Percentage, Nonperforming Loans	0.30%	0.30%
Credit Card
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days Past Due and Accruing	$ 2,072	$ 2,233
Nonperforming Loans	23	22
Credit Card \| Domestic credit card
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days Past Due and Accruing	1,948	2,111
Credit Card \| International card business
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days Past Due and Accruing	124	122
Nonperforming Loans	23	22
Consumer Banking
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days Past Due and Accruing	0	0
Nonperforming Loans	$ 352	$ 479
Percentage, Nonperforming Loans	0.59%	0.81%
Consumer Banking \| Auto
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days Past Due and Accruing	$ 0	$ 0
Nonperforming Loans	$ 321	$ 449
Percentage, Nonperforming Loans	0.57%	0.80%
Consumer Banking \| Retail banking
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days Past Due and Accruing	$ 0	$ 0
Nonperforming Loans	$ 31	$ 30
Percentage, Nonperforming Loans	1.10%	1.04%
Commercial Banking
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days Past Due and Accruing	$ 38	$ 0
Nonperforming Loans	378	312
Commercial Banking \| Total commercial lending
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days Past Due and Accruing	38	0
Nonperforming Loans	370	306
Commercial Banking \| Commercial and multifamily real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days Past Due and Accruing	0	0
Nonperforming Loans	69	83
Commercial Banking \| Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days Past Due and Accruing	38	0
Nonperforming Loans	301	223
Commercial Banking \| Small-ticket commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
90 Days Past Due and Accruing	0	0
Nonperforming Loans	$ 8	$ 6

Financing Receivable, Percent 90 Days Past Due and Still Accruing

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- Definition

Percentage of nonaccrual financing receivable balance outstanding that is past due.

+ References

No definition available.

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- Definition

Recorded investment in financing receivables that are 90 days or more past due and still accruing.

+ 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 (d)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5111-111524

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- Definition

Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

+ 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=84173941&loc=d3e5111-111524

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+ References

No definition available.

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