DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING ACTIVITIES - Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Interest rate swap agreements and non-hedging derivative assets and liabilities
Notional Amount	$ 100,033		$ 130,205
Estimated Fair Value Asset (Liability)	1,171		447
Designated as Hedging Instrument \| Cash flow hedges:
Interest rate swap agreements and non-hedging derivative assets and liabilities
Notional Amount	$ 90,000		$ 90,000
Weighted Average Maturity	4 years 10 months 13 days		5 years 1 month 6 days
Estimated Fair Value Asset (Liability)	$ 1,215		$ 669
Designated as Hedging Instrument \| Cash flow hedges: \| Interest rate caps agreements
Interest rate swap agreements and non-hedging derivative assets and liabilities
Notional Amount	$ 90,000		$ 90,000
Weighted Average Maturity	4 years 10 months 13 days		5 years 1 month 6 days
Estimated Fair Value Asset (Liability)	$ 1,215		$ 669
Realized gain (loss)	(108)	$ (39)
Designated as Hedging Instrument \| Economic hedges:
Interest rate swap agreements and non-hedging derivative assets and liabilities
Notional Amount	$ 5,658		$ 20,352
Weighted Average Maturity	2 months 12 days		2 months 12 days
Estimated Fair Value Asset (Liability)	$ (51)		$ (221)
Designated as Hedging Instrument \| Economic hedges: \| Forward sale commitments
Interest rate swap agreements and non-hedging derivative assets and liabilities
Notional Amount	$ 5,658		$ 20,352
Weighted Average Maturity	2 months 12 days		2 months 12 days
Estimated Fair Value Asset (Liability)	$ (51)		$ (221)
Realized gain (loss)	170	(78)
Not Designated as Hedging Instrument
Interest rate swap agreements and non-hedging derivative assets and liabilities
Notional Amount	$ 4,375		$ 19,853
Weighted Average Maturity	2 months 12 days		2 months 12 days
Estimated Fair Value Asset (Liability)	$ 7		$ (1)
Not Designated as Hedging Instrument \| Interest rate lock commitments
Interest rate swap agreements and non-hedging derivative assets and liabilities
Notional Amount	$ 4,375		$ 19,853
Weighted Average Maturity	2 months 12 days		2 months 12 days
Estimated Fair Value Asset (Liability)	$ 7		$ (1)
Realized gain (loss)	$ 8	$ 2

Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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

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- Definition

Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958

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- Definition

Average remaining period until maturity of the derivative contract, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

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- References

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- Definition

The difference between the book value and the sale price of options, swaps, futures, forward contracts, and other derivative instruments. This element refers to the gain (loss) included in earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.13(h))
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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