Loans - Impaired Loans, Excluding Acquired Loans (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Impaired Financing Receivable:
With an Allowance	$ 1,591	$ 2,052
Without an Allowance	253	393
Total Recorded Investment	1,844	2,445
Related Allowance	338	421
Net Recorded Investment	1,506	2,024
Unpaid Principal Balance	2,040	2,882
Average Recorded Investment	2,105	2,868	$ 2,930
Interest Income Recognized	145	155	177
Credit Card Portfolio Segment
Impaired Financing Receivable:
With an Allowance	855	812
Without an Allowance	0	0
Total Recorded Investment	855	812
Related Allowance	277	292
Net Recorded Investment	578	520
Unpaid Principal Balance	837	792
Average Recorded Investment	839	756	673
Interest Income Recognized	75	74	68
Credit Card Portfolio Segment \| Domestic credit card
Impaired Financing Receivable:
With an Allowance	666	639
Without an Allowance	0	0
Total Recorded Investment	666	639
Related Allowance	186	208
Net Recorded Investment	480	431
Unpaid Principal Balance	654	625
Average Recorded Investment	655	602	540
Interest Income Recognized	63	63	58
Credit Card Portfolio Segment \| International card business
Impaired Financing Receivable:
With an Allowance	189	173
Without an Allowance	0	0
Total Recorded Investment	189	173
Related Allowance	91	84
Net Recorded Investment	98	89
Unpaid Principal Balance	183	167
Average Recorded Investment	184	154	133
Interest Income Recognized	12	11	10
Consumer Portfolio Segment
Impaired Financing Receivable:
With an Allowance	343	606
Without an Allowance	50	169
Total Recorded Investment	393	775
Related Allowance	27	53
Net Recorded Investment	366	722
Unpaid Principal Balance	480	1,094
Average Recorded Investment	547	853	924
Interest Income Recognized	48	59	93
Consumer Portfolio Segment \| Auto
Impaired Financing Receivable:
With an Allowance	301	363
Without an Allowance	38	118
Total Recorded Investment	339	481
Related Allowance	22	30
Net Recorded Investment	317	451
Unpaid Principal Balance	420	730
Average Recorded Investment	397	495	501
Interest Income Recognized	45	53	86
Consumer Portfolio Segment \| Home loan
Impaired Financing Receivable:
With an Allowance		192
Without an Allowance		41
Total Recorded Investment		233
Related Allowance		15
Net Recorded Investment		218
Unpaid Principal Balance		298
Average Recorded Investment	91	299	361
Interest Income Recognized	1	5	5
Consumer Portfolio Segment \| Retail banking
Impaired Financing Receivable:
With an Allowance	42	51
Without an Allowance	12	10
Total Recorded Investment	54	61
Related Allowance	5	8
Net Recorded Investment	49	53
Unpaid Principal Balance	60	66
Average Recorded Investment	59	59	62
Interest Income Recognized	2	1	2
Commercial Banking
Impaired Financing Receivable:
With an Allowance	393	634
Without an Allowance	203	224
Total Recorded Investment	596	858
Related Allowance	34	76
Net Recorded Investment	562	782
Unpaid Principal Balance	723	996
Average Recorded Investment	719	1,259	1,333
Interest Income Recognized	22	22	16
Commercial Banking \| Total commercial lending
Impaired Financing Receivable:
With an Allowance	393	627
Without an Allowance	197	224
Total Recorded Investment	590	851
Related Allowance	34	76
Net Recorded Investment	556	775
Unpaid Principal Balance	714	987
Average Recorded Investment	714	1,252	1,326
Interest Income Recognized	22	22	16
Commercial Banking \| Commercial and multifamily real estate
Impaired Financing Receivable:
With an Allowance	92	138
Without an Allowance	28	2
Total Recorded Investment	120	140
Related Allowance	5	13
Net Recorded Investment	115	127
Unpaid Principal Balance	121	143
Average Recorded Investment	93	134	111
Interest Income Recognized	2	4	3
Commercial Banking \| Commercial and industrial
Impaired Financing Receivable:
With an Allowance	301	489
Without an Allowance	169	222
Total Recorded Investment	470	711
Related Allowance	29	63
Net Recorded Investment	441	648
Unpaid Principal Balance	593	844
Average Recorded Investment	621	1,118	1,215
Interest Income Recognized	20	18	13
Commercial Banking \| Small-ticket commercial real estate
Impaired Financing Receivable:
With an Allowance	0	7
Without an Allowance	6	0
Total Recorded Investment	6	7
Related Allowance	0	0
Net Recorded Investment	6	7
Unpaid Principal Balance	9	9
Average Recorded Investment	5	7	7
Interest Income Recognized	$ 0	$ 0	$ 0

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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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
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-Publisher FASB
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-Topic 310
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-Section 50
-Paragraph 14A
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