GOODWILL AND INTANGIBLE ASSETS - Changes in Intangible Assets (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
Sep. 30, 2017	Dec. 31, 2016
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2016, Intangible assets (excluding MSRs)	$ 5,114
Acquisitions/ divestitures	15
Amortization	(450)
FX translation and other	53
Net carrying amount at September 30, 2017, Intangible assets (excluding MSRs)	4,732	$ 5,114
Mortgage servicing rights (MSRs)	553	1,564
Total intangible assets	5,285	6,678
Indefinite-lived intangible assets
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2016, Intangible assets (excluding MSRs)	210
Acquisitions/ divestitures	0
Amortization	0
FX translation and other	22
Net carrying amount at September 30, 2017, Intangible assets (excluding MSRs)	232	210
Purchased credit card relationships
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2016, Intangible assets (excluding MSRs)	1,666
Acquisitions/ divestitures	20
Amortization	(109)
FX translation and other	2
Net carrying amount at September 30, 2017, Intangible assets (excluding MSRs)	1,579	1,666
Credit card contract related intangibles
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2016, Intangible assets (excluding MSRs)	2,972
Acquisitions/ divestitures	9
Amortization	(295)
FX translation and other	2
Net carrying amount at September 30, 2017, Intangible assets (excluding MSRs)	2,688	2,972
Core deposit intangibles
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2016, Intangible assets (excluding MSRs)	30
Acquisitions/ divestitures	0
Amortization	(18)
FX translation and other	2
Net carrying amount at September 30, 2017, Intangible assets (excluding MSRs)	14	30
Other customer relationships
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2016, Intangible assets (excluding MSRs)	202
Acquisitions/ divestitures	0
Amortization	(17)
FX translation and other	8
Net carrying amount at September 30, 2017, Intangible assets (excluding MSRs)	193	202
Present value of future profits
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2016, Intangible assets (excluding MSRs)	4
Acquisitions/ divestitures	0
Amortization	0
FX translation and other	0
Net carrying amount at September 30, 2017, Intangible assets (excluding MSRs)	4	4
Other
Finite and Indefinite-lived Intangible Assets
Net carrying amount at December 31, 2016, Intangible assets (excluding MSRs)	30
Acquisitions/ divestitures	(14)
Amortization	(11)
FX translation and other	17
Net carrying amount at September 30, 2017, Intangible assets (excluding MSRs)	$ 22	$ 30
American Airlines, Sears, The Home Depot, Costco and AT&T \| Customer Concentration Risk \| Intangible Assets, Excluding Mortgage Servicing Rights \| Credit card contract related intangibles
Finite and Indefinite-lived Intangible Assets
Concentration risk, percentage	97.00%	97.00%

No definition available.

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- Definition

Sum of the carrying amounts of all intangible assets, excluding goodwill and excluding mortgage servicing rights, as of the balance sheet date, net of accumulated amortization and impairment charges.

+ References

No definition available.

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Intangible Assets, Excluding Mortgage Servicing Rights Acquisitions (Divestitures)

+ References

No definition available.

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- Definition

This element represents the aggregate amount of amortization of intangible assets excluding mortgage servicing rights (MSRs) during the period.

+ References

No definition available.

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This element represents net changes to the recorded value of intangible assets excluding mortgage servicing rights (MSRs), due to foreign currency translation adjustments and purchase accounting adjustments.

+ References

No definition available.

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This element represents the sum of the carrying amounts of all intangible assets excluding goodwill but including mortgage servicing rights, as of the balance sheet date that is net of accumulated amortization and impairment charges.

+ References

No definition available.

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The amount of mortgage servicing rights (MSRs) as of the balance sheet date.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13537-108611

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