Loans - TDR - Subsequent Defaults of Completed TDR Modifications (Detail) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2017 USD ($) Contract	Jun. 30, 2016 USD ($) Contract	Jun. 30, 2017 USD ($) Contract	Jun. 30, 2016 USD ($) Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts \| Contract	29,555	22,292	56,001	43,593
Total Loans \| $	$ 176	$ 76	$ 267	$ 161
Credit Card Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts \| Contract	26,983	20,203	51,213	39,610
Total Loans \| $	$ 52	$ 37	$ 94	$ 75
Consumer Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts \| Contract	2,550	2,084	4,751	3,961
Total Loans \| $	$ 35	$ 25	$ 64	$ 49
Consumer Portfolio Segment [Member] \| Auto
Financing Receivable, Modifications [Line Items]
Number of Contracts \| Contract	2,533	2,061	4,712	3,913
Total Loans \| $	$ 30	$ 22	$ 55	$ 43
Consumer Portfolio Segment [Member] \| Home loan
Financing Receivable, Modifications [Line Items]
Number of Contracts \| Contract	8	13	19	23
Total Loans \| $	$ 3	$ 2	$ 6	$ 3
Consumer Portfolio Segment [Member] \| Retail banking
Financing Receivable, Modifications [Line Items]
Number of Contracts \| Contract	9	10	20	25
Total Loans \| $	$ 2	$ 1	$ 3	$ 3
Commercial Banking
Financing Receivable, Modifications [Line Items]
Number of Contracts \| Contract	22	5	37	22
Total Loans \| $	$ 89	$ 14	$ 109	$ 37
Commercial Banking \| Total commercial lending
Financing Receivable, Modifications [Line Items]
Number of Contracts \| Contract	21	3	35	20
Total Loans \| $	$ 89	$ 14	$ 108	$ 37
Commercial Banking \| Commercial and multifamily real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts \| Contract	0	0	0	0
Total Loans \| $	$ 0	$ 0	$ 0	$ 0
Commercial Banking \| Commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of Contracts \| Contract	21	3	35	20
Total Loans \| $	$ 89	$ 14	$ 108	$ 37
Commercial Banking \| Small-ticket commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Contracts \| Contract	1	2	2	2
Total Loans \| $	$ 0	$ 0	$ 1	$ 0
Geographic Distribution, Domestic [Member] \| Credit Card Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts \| Contract	13,222	10,231	26,027	20,825
Total Loans \| $	$ 25	$ 16	$ 51	$ 34
Geographic Distribution, Foreign [Member] \| Credit Card Portfolio Segment [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts \| Contract	13,761	9,972	25,186	18,785
Total Loans \| $	$ 27	$ 21	$ 43	$ 41

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL6953682-111524

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Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

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