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LOAN LOSS ALLOWANCE - Narrative (Details) - Business Activities Loans	12 Months Ended
	Dec. 31, 2019 grade
Financing Receivable, Credit Quality Indicator [Line Items]
Number of grades in internal loan rating system (grade)	3
Residential | Mortgages | Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Period within which loans are current, based on which risk rating is assigned	59 days
Residential | Mortgages | Special mention | Minimum
Financing Receivable, Credit Quality Indicator [Line Items]
Delinquency period of loans based on which risk rating is assigned	60 days
Residential | Mortgages | Special mention | Maximum
Financing Receivable, Credit Quality Indicator [Line Items]
Delinquency period of loans based on which risk rating is assigned	89 days
Residential | Mortgages | Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Delinquency period of loans based on which risk rating is assigned	90 days
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Number of grades in internal loan rating system (grade)	2
Consumer | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Period within which loans are current, based on which risk rating is assigned	119 days
Consumer | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Delinquency period of loans based on which risk rating is assigned	120 days

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