LOANS (Schedule of Loan Balances by Portfolio Class) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2017	Dec. 31, 2016
Total loans	$ 3,664,858	$ 3,310,104
Net deferred fees	2,339	2,040
Total loans including net deferred costs	3,667,197	3,312,144
Construction Loans [Member]
Total loans including net deferred costs		1,405
Residential Portfolio Segment [Member] \| Junior Lien [Member]
Total loans	7,082	9,206
Residential Portfolio Segment [Member] \| Primary Residential Mortgages [Member]
Total loans	631,632	557,970
Residential Portfolio Segment [Member] \| Home Equity Lines of Credit [Member]
Total loans	68,787	65,683
Total loans including net deferred costs	68,787	65,682
Residential Portfolio Segment [Member] \| Multifamily Property [Member]
Total loans	1,441,852	1,459,594
Total loans including net deferred costs	1,441,852	1,459,594
Commercial Real Estate Portfolio Segment [Member] \| Owner Occupied Property [Member]
Total loans	253,605	176,123
Commercial Real Estate Portfolio Segment [Member] \| Investment Property [Member]
Total loans	876,282	752,258
Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Total loans	93	1,497
Consumer and Other [Member]
Total loans	92,055	73,621
Commercial and Industrial Sector [Member] \| Commercial Portfolio Segment [Member]
Total loans	257,124	213,983
Lease Financing [Member]
Total loans	36,184
Lease Financing [Member] \| Commercial Portfolio Segment [Member]
Total loans	36,184
Agricultural Sector [Member]
Total loans	$ 162	$ 169
Loans and Finance Receivables, Gross [Member]
Total loans (in percent)	100.00%	100.00%
Loans and Finance Receivables, Gross [Member] \| Residential Portfolio Segment [Member] \| Junior Lien [Member]
Total loans (in percent)	0.19%	0.28%
Loans and Finance Receivables, Gross [Member] \| Residential Portfolio Segment [Member] \| Primary Residential Mortgages [Member]
Total loans (in percent)	17.23%	16.86%
Loans and Finance Receivables, Gross [Member] \| Residential Portfolio Segment [Member] \| Home Equity Lines of Credit [Member]
Total loans (in percent)	1.88%	1.98%
Loans and Finance Receivables, Gross [Member] \| Residential Portfolio Segment [Member] \| Multifamily Property [Member]
Total loans (in percent)	39.34%	44.09%
Loans and Finance Receivables, Gross [Member] \| Commercial Real Estate Portfolio Segment [Member] \| Owner Occupied Property [Member]
Total loans (in percent)	6.92%	5.32%
Loans and Finance Receivables, Gross [Member] \| Commercial Real Estate Portfolio Segment [Member] \| Investment Property [Member]
Total loans (in percent)	23.91%	22.73%
Loans and Finance Receivables, Gross [Member] \| Commercial Portfolio Segment [Member] \| Construction Loans [Member]
Total loans (in percent)	0.01%	0.04%
Loans and Finance Receivables, Gross [Member] \| Consumer and Other [Member]
Total loans (in percent)	2.51%	2.22%
Loans and Finance Receivables, Gross [Member] \| Commercial and Industrial Sector [Member] \| Commercial Portfolio Segment [Member]
Total loans (in percent)	7.01%	6.47%
Loans and Finance Receivables, Gross [Member] \| Lease Financing [Member] \| Commercial Portfolio Segment [Member]
Total loans (in percent)	0.99%
Loans and Finance Receivables, Gross [Member] \| Agricultural Sector [Member]
Total loans (in percent)	0.01%	0.01%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6351-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13531-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=84177426&loc=d3e6404-108592

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
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-Section 50
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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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Amount before allowance and after 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
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-URI http://asc.fasb.org/extlink&oid=82891408&loc=d3e4428-111522

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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
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-Name Accounting Standards Codification
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-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6378536&loc=d3e10092-111533

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