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LOANS, Loan Summary (Details) - USD ($) $ in Thousands | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Loans receivable, net [Abstract] |  |  |  |
Gross loans, including deferred origination costs | $ 6,256,757 | $ 4,948,562 |  |
Allowance for loan losses | (47,583) | (47,233) | $ (45,401) | $ (45,341)
Net loans | 6,209,174 | 4,901,329 |  |
Net deferred loan origination costs | 25,300 | 22,800 |  |
Loans receivable, related parties [Roll Forward] |  |  |  |
Balance at beginning of year | 10,950 | 11,337 |  |
New loans | 16,617 | 4,959 |  |
Payments | (5,223) | (5,346) |  |
Balance at end of year | $ 22,344 | 10,950 |  |
Consumer Mortgage [Member] | Minimum [Member] |  |  |  |
Loans receivable, net [Abstract] |  |  |  |
Typical contract term | 10 years |  |  |
Consumer Mortgage [Member] | Maximum [Member] |  |  |  |
Loans receivable, net [Abstract] |  |  |  |
Typical contract term | 30 years |  |  |
Business Lending [Member] |  |  |  |
Loans receivable, net [Abstract] |  |  |  |
Gross loans, including deferred origination costs | $ 2,424,223 | 1,490,076 |  |
Home Equity [Member] | Maximum [Member] |  |  |  |
Loans receivable, net [Abstract] |  |  |  |
Typical contract term | 30 years |  |  |
Residential Portfolio Segment [Member] | Consumer Mortgage [Member] |  |  |  |
Loans receivable, net [Abstract] |  |  |  |
Gross loans, including deferred origination costs | $ 2,220,298 | 1,819,701 |  |
Allowance for loan losses | (10,465) | (10,094) | (10,198) | (10,286)
Commercial Portfolio Segment [Member] | Business Lending [Member] |  |  |  |
Loans receivable, net [Abstract] |  |  |  |
Gross loans, including deferred origination costs | 2,424,223 | 1,490,076 |  |
Allowance for loan losses | (17,257) | (17,220) | (15,749) | (15,787)
Consumer Portfolio Segment [Member] | Consumer Indirect [Member] |  |  |  |
Loans receivable, net [Abstract] |  |  |  |
Gross loans, including deferred origination costs | 1,011,978 | 1,044,972 |  |
Allowance for loan losses | (13,468) | (13,782) | (12,422) | (11,544)
Consumer Portfolio Segment [Member] | Consumer Direct [Member] |  |  |  |
Loans receivable, net [Abstract] |  |  |  |
Gross loans, including deferred origination costs | 179,929 | 191,815 |  |
Allowance for loan losses | (3,039) | (2,979) | (2,997) | (3,083)
Consumer Portfolio Segment [Member] | Home Equity [Member] |  |  |  |
Loans receivable, net [Abstract] |  |  |  |
Gross loans, including deferred origination costs | 420,329 | 401,998 |  |
Allowance for loan losses | $ (2,107) | $ (2,399) | $ (2,666) | $ (2,701)

X
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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) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(d)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SAB Topic 6.L.1) -URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74567-122707 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (b)(1)(ii) -URI http://asc.fasb.org/extlink&oid=82894903&loc=d3e15032-111544 + Details
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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 -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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