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DERIVATIVE FINANCIAL INSTRUMENTS - Narrative (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Derivative [Line Items] |  |  |
Ineffectiveness included in net income | $ 0 | $ 0 |
Interest expense | 12,152,000 | 10,868,000 | $ 8,323,000
Unrealized loss to be reclassified as a reduction of interest expense | 0 |  |
Designated as Hedging Instrument | Cash Flow Hedging | Interest Rate Swap |  |  |
Derivative [Line Items] |  |  |
Notional amount | 5,000,000 | 5,000 |
Interest expense | $ 724,000 | $ 882,000 | $ 603,000

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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
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- Definition The net gain (loss) recognized in earnings during the reporting period representing the amount of the cash flow hedges' ineffectiveness. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959 + Details
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