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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-Section 50
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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The number of businesses acquired by the entity during the period.

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Number of reporting units tested for impairment of goodwill. A reporting unit is an operating segment or one level below an operating segment.

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GOODWILL - Narrative (Details)	12 Months Ended			348 Months Ended
GOODWILL - Narrative (Details)	Dec. 31, 2016 USD ($) reporting_unit	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2016 USD ($) business
Goodwill [Line Items]
Number of acquisitions of banks or assets of banks \| business				25
Number of reporting units \| reporting_unit	2
Goodwill impairment	$ 0	$ 0	$ 0
Consumer Banking
Goodwill [Line Items]
Goodwill accumulated impairment loss	5,900,000,000	5,900,000,000		$ 5,900,000,000
Commercial Banking
Goodwill [Line Items]
Goodwill accumulated impairment loss	$ 50,000,000	$ 50,000,000		$ 50,000,000