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Loans - TDR - Subsequent Defaults of Completed TDR Modifications (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($) Contract	Mar. 31, 2019 USD ($) Contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	30,025	31,846
Total Loans | $	$ 92	$ 70
Credit Card
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	28,743	30,733
Total Loans | $	$ 48	$ 57
Consumer Banking
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	1,276	1,113
Total Loans | $	$ 16	$ 13
Consumer Banking | Auto
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	1,275	1,105
Total Loans | $	$ 16	$ 13
Consumer Banking | Retail banking
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	1	8
Total Loans | $	$ 0	$ 0
Commercial Banking
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	6	0
Total Loans | $	$ 28	$ 0
Commercial Banking | Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	6	0
Total Loans | $	$ 28	$ 0
Domestic credit card: | Credit Card
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	10,886	14,027
Total Loans | $	$ 22	$ 29
International card businesses: | Credit Card
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts | Contract	17,857	16,706
Total Loans | $	$ 26	$ 28

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Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953682-111524

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Amount of financing receivable modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953682-111524

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