LOANS, Loan Summary (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	$ 4,801,375	$ 4,236,206
Allowance for loan losses	(45,401)	(45,341)	$ (44,319)
Net loans	4,755,974	4,190,865
Net deferred loan origination costs	20,000	18,700
Loans receivable, related parties [Roll Forward]
Balance at beginning of year	8,928	9,448
New loans	5,138	1,647
Payments	(2,729)	(2,167)
Balance at end of year	$ 11,337	8,928
Consumer Mortgage [Member] \| Minimum [Member]
Loans receivable, net [Abstract]
Contract term of loans	10 years
Consumer Mortgage [Member] \| Maximum [Member]
Loans receivable, net [Abstract]
Contract term of loans	30 years
Business Lending [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	$ 1,497,271	1,262,484
Home Equity [Member] \| Maximum [Member]
Loans receivable, net [Abstract]
Contract term of loans	30 years
Residential Portfolio Segment [Member] \| Consumer Mortgage [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	$ 1,769,754	1,613,384
Allowance for loan losses	(10,198)	(10,286)	(8,994)
Commercial Portfolio Segment [Member] \| Business Lending [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	1,497,271	1,262,484
Allowance for loan losses	(15,749)	(15,787)	(17,507)
Consumer Portfolio Segment [Member] \| Consumer Indirect [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	935,760	833,968
Allowance for loan losses	(12,422)	(11,544)	(10,248)
Consumer Portfolio Segment [Member] \| Consumer Direct [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	195,076	184,028
Allowance for loan losses	(2,997)	(3,083)	(3,181)
Consumer Portfolio Segment [Member] \| Home Equity [Member]
Loans receivable, net [Abstract]
Gross loans, including deferred origination costs	403,514	342,342
Allowance for loan losses	$ (2,666)	$ (2,701)	$ (1,830)

The typical original contract term of financial receivable.

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- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (g)
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-Publisher FASB
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-Section S99
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 6
-Section L
-Subsection 1

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- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

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- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
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- Definition

For an unclassified balance sheet, reflects the carrying amount of unpaid loan amounts due from related parties at the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
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- Definition

Reflects the amount of new advances made to related parties in the form of loan and lease receivables.

+ References

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- Definition

Reflects the amount of collections received from related parties to reduce the carrying amounts of loans and leases receivable due from them.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

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- Definition

Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6378536&loc=d3e10092-111533

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