Loans - Impaired Loans, Excluding Acquired Loans (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014
Impaired Financing Receivable:
With an Allowance	$ 1,822	$ 1,469
Without an Allowance	642	445
Total Recorded Investment	2,464	1,914
Related Allowance	349	300
Net Recorded Investment	2,115	1,614
Unpaid Principal Balance	2,894	2,296
Average Recorded Investment	2,138	1,943
Interest Income Recognized	163	158
Credit Card Portfolio Segment [Member]
Impaired Financing Receivable:
With an Allowance	666	692
Without an Allowance	0	0
Total Recorded Investment	666	692
Related Allowance	209	219
Net Recorded Investment	457	473
Unpaid Principal Balance	647	672
Average Recorded Investment	674	731
Interest Income Recognized	67	69
Consumer Portfolio Segment [Member]
Impaired Financing Receivable:
With an Allowance	553	493
Without an Allowance	361	359
Total Recorded Investment	914	852
Related Allowance	54	42
Net Recorded Investment	860	810
Unpaid Principal Balance	1,290	1,218
Average Recorded Investment	882	844
Interest Income Recognized	88	79
Consumer Portfolio Segment [Member] \| Auto
Impaired Financing Receivable:
With an Allowance	273	230
Without an Allowance	215	205
Total Recorded Investment	488	435
Related Allowance	22	19
Net Recorded Investment	466	416
Unpaid Principal Balance	772	694
Average Recorded Investment	462	387
Interest Income Recognized	82	72
Consumer Portfolio Segment [Member] \| Home loan
Impaired Financing Receivable:
With an Allowance	229	218
Without an Allowance	136	149
Total Recorded Investment	365	367
Related Allowance	18	17
Net Recorded Investment	347	350
Unpaid Principal Balance	456	472
Average Recorded Investment	364	388
Interest Income Recognized	4	5
Consumer Portfolio Segment [Member] \| Retail banking
Impaired Financing Receivable:
With an Allowance	51	45
Without an Allowance	10	5
Total Recorded Investment	61	50
Related Allowance	14	6
Net Recorded Investment	47	44
Unpaid Principal Balance	62	52
Average Recorded Investment	56	69
Interest Income Recognized	2	2
Commercial Banking
Impaired Financing Receivable:
With an Allowance	603	284
Without an Allowance	281	86
Total Recorded Investment	884	370
Related Allowance	86	39
Net Recorded Investment	798	331
Unpaid Principal Balance	957	406
Average Recorded Investment	582	368
Interest Income Recognized	8	10
Commercial Banking \| Total commercial lending
Impaired Financing Receivable:
With an Allowance	597	281
Without an Allowance	281	81
Total Recorded Investment	878	362
Related Allowance	86	39
Net Recorded Investment	792	323
Unpaid Principal Balance	950	396
Average Recorded Investment	575	360
Interest Income Recognized	8	10
Commercial Banking \| Commercial and multifamily real estate
Impaired Financing Receivable:
With an Allowance	82	120
Without an Allowance	3	26
Total Recorded Investment	85	146
Related Allowance	11	23
Net Recorded Investment	74	123
Unpaid Principal Balance	88	163
Average Recorded Investment	109	175
Interest Income Recognized	3	6
Commercial Banking \| Commercial and industrial
Impaired Financing Receivable:
With an Allowance	515	161
Without an Allowance	278	55
Total Recorded Investment	793	216
Related Allowance	75	16
Net Recorded Investment	718	200
Unpaid Principal Balance	862	233
Average Recorded Investment	466	185
Interest Income Recognized	5	4
Commercial Banking \| Small-ticket commercial real estate
Impaired Financing Receivable:
With an Allowance	6	3
Without an Allowance	0	5
Total Recorded Investment	6	8
Related Allowance	0	0
Net Recorded Investment	6	8
Unpaid Principal Balance	7	10
Average Recorded Investment	7	8
Interest Income Recognized	0	0
Geographic Distribution, Foreign [Member] \| Credit Card Portfolio Segment [Member]
Impaired Financing Receivable:
With an Allowance	125	146
Without an Allowance	0	0
Total Recorded Investment	125	146
Related Allowance	59	74
Net Recorded Investment	66	72
Unpaid Principal Balance	121	141
Average Recorded Investment	135	160
Interest Income Recognized	10	11
Geographic Distribution, Domestic [Member] \| Credit Card Portfolio Segment [Member]
Impaired Financing Receivable:
With an Allowance	541	546
Without an Allowance	0	0
Total Recorded Investment	541	546
Related Allowance	150	145
Net Recorded Investment	391	401
Unpaid Principal Balance	526	531
Average Recorded Investment	539	571
Interest Income Recognized	$ 57	$ 58

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5212-111524

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5258-111524

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953550-111524

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