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Goodwill and Intangible Assets - Goodwill Business Segments (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2020 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 14,653
Other adjustments	(5)
Goodwill, ending balance	14,648
Credit Card
Goodwill [Roll Forward]
Goodwill, beginning balance	5,088
Other adjustments	(5)
Goodwill, ending balance	5,083
Consumer Banking
Goodwill [Roll Forward]
Goodwill, beginning balance	4,645
Other adjustments	0
Goodwill, ending balance	4,645
Commercial Banking
Goodwill [Roll Forward]
Goodwill, beginning balance	4,920
Other adjustments	0
Goodwill, ending balance	$ 4,920

X

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(10)(1))
-URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=120320667&loc=SL49117168-202975

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266

+ Details

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Namespace Prefix:	us-gaap_
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Period Type:	instant

X

- Definition

Amount of increase (decrease), classified as other, of an asset representing the future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=121556970&loc=d3e13816-109267

+ Details

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X

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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X

- Details

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X

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