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ACCOUNTING POLICIES (Details) $ in Thousands | 3 Months Ended
--- | ---
Mar. 31, 2018 USD ($) Component Calculation Segment Factor | Mar. 31, 2017 USD ($)
Financing Receivable, Allowance for Credit Losses [Line Items] |  |
Number of broad components used in allowance methodology | Component | 2 |
Number of calculations used for general loan loss allocation | Calculation | 2 |
Number of main loan segments | Segment | 5 |
Period of historical net charge-off data for each loan class used in determining allowance level | 36 months |
Number of qualitative environmental factors used in qualitative calculation for loan loss allocation | Factor | 8 |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |
Salaries and employee benefits | $ 51,859 | $ 42,907
Other expenses | $ 2,938 | 2,545
Core Deposits [Member] | Minimum [Member] |  |
Finite-Lived Intangible Assets [Line Items] |  |
Intangible asset useful life (amortization period) | 7 years |
Core Deposits [Member] | Maximum [Member] |  |
Finite-Lived Intangible Assets [Line Items] |  |
Intangible asset useful life (amortization period) | 20 years |
Customer Relationships [Member] | Minimum [Member] |  |
Finite-Lived Intangible Assets [Line Items] |  |
Intangible asset useful life (amortization period) | 7 years |
Customer Relationships [Member] | Maximum [Member] |  |
Finite-Lived Intangible Assets [Line Items] |  |
Intangible asset useful life (amortization period) | 20 years |
Commercial Portfolio Segment [Member] | Minimum [Member] |  |
Financing Receivable, Allowance for Credit Losses [Line Items] |  |
Threshold balance of loans individually evaluated for impairment | $ 500 |
ASU 2017-07 [Member] |  |
New Accounting Pronouncements or Change in Accounting Principle [Line Items] |  |
Salaries and employee benefits |  | (1,500)
Other expenses |  | $ 1,500

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