Loans - Impaired Loans, Excluding Acquired Loans (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Impaired Financing Receivable:
With an Allowance	$ 1,689	$ 1,591
Without an Allowance	203	253
Total Recorded Investment	1,892	1,844
Related Allowance	354	338
Net Recorded Investment	1,538	1,506
Unpaid Principal Balance	2,185	2,040
Average Recorded Investment	1,890	2,105	$ 2,868
Interest Income Recognized	126	145	155
Credit Card
Impaired Financing Receivable:
With an Allowance	831	855
Without an Allowance	0	0
Total Recorded Investment	831	855
Related Allowance	210	277
Net Recorded Investment	621	578
Unpaid Principal Balance	815	837
Average Recorded Investment	837	839	756
Interest Income Recognized	71	75	74
Credit Card \| Domestic credit card
Impaired Financing Receivable:
With an Allowance	630	666
Without an Allowance	0	0
Total Recorded Investment	630	666
Related Allowance	122	186
Net Recorded Investment	508	480
Unpaid Principal Balance	620	654
Average Recorded Investment	643	655	602
Interest Income Recognized	57	63	63
Credit Card \| International card business
Impaired Financing Receivable:
With an Allowance	201	189
Without an Allowance	0	0
Total Recorded Investment	201	189
Related Allowance	88	91
Net Recorded Investment	113	98
Unpaid Principal Balance	195	183
Average Recorded Investment	194	184	154
Interest Income Recognized	14	12	11
Consumer Banking
Impaired Financing Receivable:
With an Allowance	344	343
Without an Allowance	44	50
Total Recorded Investment	388	393
Related Allowance	28	27
Net Recorded Investment	360	366
Unpaid Principal Balance	500	480
Average Recorded Investment	390	547	853
Interest Income Recognized	40	48	59
Consumer Banking \| Auto
Impaired Financing Receivable:
With an Allowance	305	301
Without an Allowance	41	38
Total Recorded Investment	346	339
Related Allowance	24	22
Net Recorded Investment	322	317
Unpaid Principal Balance	454	420
Average Recorded Investment	339	397	495
Interest Income Recognized	39	45	53
Consumer Banking \| Home loan
Impaired Financing Receivable:
Average Recorded Investment	0	91	299
Interest Income Recognized	0	1	5
Consumer Banking \| Retail banking
Impaired Financing Receivable:
With an Allowance	39	42
Without an Allowance	3	12
Total Recorded Investment	42	54
Related Allowance	4	5
Net Recorded Investment	38	49
Unpaid Principal Balance	46	60
Average Recorded Investment	51	59	59
Interest Income Recognized	1	2	1
Commercial Banking
Impaired Financing Receivable:
With an Allowance	514	393
Without an Allowance	159	203
Total Recorded Investment	673	596
Related Allowance	116	34
Net Recorded Investment	557	562
Unpaid Principal Balance	870	723
Average Recorded Investment	663	719	1,259
Interest Income Recognized	15	22	22
Commercial Banking \| Total commercial lending
Impaired Financing Receivable:
With an Allowance		393
Without an Allowance		197
Total Recorded Investment		590
Related Allowance		34
Net Recorded Investment		556
Unpaid Principal Balance		714
Average Recorded Investment	659	714	1,252
Interest Income Recognized	15	22	22
Commercial Banking \| Commercial and multifamily real estate
Impaired Financing Receivable:
With an Allowance	33	92
Without an Allowance	34	28
Total Recorded Investment	67	120
Related Allowance	1	5
Net Recorded Investment	66	115
Unpaid Principal Balance	70	121
Average Recorded Investment	88	93	134
Interest Income Recognized	1	2	4
Commercial Banking \| Commercial and industrial
Impaired Financing Receivable:
With an Allowance	481	301
Without an Allowance	125	169
Total Recorded Investment	606	470
Related Allowance	115	29
Net Recorded Investment	491	441
Unpaid Principal Balance	800	593
Average Recorded Investment	571	621	1,118
Interest Income Recognized	14	20	18
Commercial Banking \| Small-ticket commercial real estate
Impaired Financing Receivable:
With an Allowance		0
Without an Allowance		6
Total Recorded Investment		6
Related Allowance		0
Net Recorded Investment		6
Unpaid Principal Balance		9
Average Recorded Investment	4	5	7
Interest Income Recognized	$ 0	$ 0	$ 0

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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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5212-111524

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-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5258-111524

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Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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-Publisher FASB
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-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953550-111524

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