FAIR VALUE (Schedule of Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Financial Assets:
Securities available for sale	$ 249,616	$ 195,630
FHLB and FRB Stock	14,093	13,984
Loans held for sale, at fair value	3,013	1,558
Multifamily mortgage loans held for sale, at lower of cost or fair value	30,000	82,200
Accrued interest receivable	6,383	6,820
Financial Liabilities:
Federal home loan bank advances	71,795	83,700
Fair value [Member]
Financial Assets:
Cash and cash equivalents	159,555	70,160
Securities available for sale	249,616	195,630
FHLB and FRB Stock
Loans held for sale, at fair value	3,013	1,558
Multifamily mortgage loans held for sale, at lower of cost or fair value	30,000	82,200
Loans, net of allowance for loan losses	3,205,692	2,865,601
Accrued interest receivable	6,383	6,820
Financial Liabilities:
Deposits	3,307,107	2,933,526
Overnight borrowings		40,700
Federal home loan bank advances	72,667	84,409
Subordinated debt	48,721
Accrued interest payable	2,025	957
Fair value [Member] | Not Designated as Hedging Instrument [Member]
Financial Assets:
Derivatives	3,656	1,106
Financial Liabilities:
Derivatives	3,656	1,106
Fair value [Member] | Designated as Hedging Instrument [Member]
Financial Assets:
Derivatives		104
Financial Liabilities:
Derivatives	4,710	1,434
Carrying Value [Member]
Financial Assets:
Cash and cash equivalents	159,555	70,160
Securities available for sale	249,616	195,630
FHLB and FRB Stock	14,093	13,984
Loans held for sale, at fair value	3,013	1,558
Multifamily mortgage loans held for sale, at lower of cost or fair value	30,000	82,200
Loans, net of allowance for loan losses	3,202,271	2,887,386
Accrued interest receivable	6,383	6,820
Financial Liabilities:
Deposits	3,300,060	2,935,470
Overnight borrowings		40,700
Federal home loan bank advances	71,795	83,692
Subordinated debt	48,731
Accrued interest payable	2,025	957
Carrying Value [Member] | Not Designated as Hedging Instrument [Member]
Financial Assets:
Derivatives	3,656	1,106
Financial Liabilities:
Derivatives	3,656	1,106
Carrying Value [Member] | Designated as Hedging Instrument [Member]
Financial Assets:
Derivatives		104
Financial Liabilities:
Derivatives	4,710	1,434
Significant Unobservable Inputs (Level 3) [Member] | Fair value [Member]
Financial Assets:
Cash and cash equivalents
Securities available for sale
FHLB and FRB Stock
Loans held for sale, at fair value
Multifamily mortgage loans held for sale, at lower of cost or fair value
Loans, net of allowance for loan losses	3,205,692	2,865,601
Accrued interest receivable	5,654	6,258
Financial Liabilities:
Deposits
Overnight borrowings
Federal home loan bank advances
Subordinated debt	48,721
Accrued interest payable	900
Significant Unobservable Inputs (Level 3) [Member] | Fair value [Member] | Not Designated as Hedging Instrument [Member]
Financial Assets:
Derivatives
Financial Liabilities:
Derivatives
Significant Unobservable Inputs (Level 3) [Member] | Fair value [Member] | Designated as Hedging Instrument [Member]
Financial Assets:
Derivatives
Financial Liabilities:
Derivatives
Significant Other Observable Inputs (Level 2) [Member] | Fair value [Member]
Financial Assets:
Cash and cash equivalents
Securities available for sale	244,636	192,691
FHLB and FRB Stock
Loans held for sale, at fair value	3,013	1,558
Multifamily mortgage loans held for sale, at lower of cost or fair value	30,000	82,200
Loans, net of allowance for loan losses
Accrued interest receivable	729	562
Financial Liabilities:
Deposits	566,740	526,226
Overnight borrowings		40,700
Federal home loan bank advances	72,667	84,409
Subordinated debt
Accrued interest payable	974	829
Significant Other Observable Inputs (Level 2) [Member] | Fair value [Member] | Not Designated as Hedging Instrument [Member]
Financial Assets:
Derivatives	3,656	1,106
Financial Liabilities:
Derivatives	3,656	1,106
Significant Other Observable Inputs (Level 2) [Member] | Fair value [Member] | Designated as Hedging Instrument [Member]
Financial Assets:
Derivatives		104
Financial Liabilities:
Derivatives	4,710	1,434
Quoted Prices in Active Market For Identical Assets (Level 1) [Member] | Fair value [Member]
Financial Assets:
Cash and cash equivalents	159,555	70,160
Securities available for sale	4,980	2,939
FHLB and FRB Stock
Loans held for sale, at fair value
Multifamily mortgage loans held for sale, at lower of cost or fair value
Loans, net of allowance for loan losses
Accrued interest receivable
Financial Liabilities:
Deposits	2,740,367	2,407,300
Overnight borrowings
Federal home loan bank advances
Subordinated debt
Accrued interest payable	151	128
Quoted Prices in Active Market For Identical Assets (Level 1) [Member] | Fair value [Member] | Not Designated as Hedging Instrument [Member]
Financial Assets:
Derivatives
Financial Liabilities:
Derivatives
Quoted Prices in Active Market For Identical Assets (Level 1) [Member] | Fair value [Member] | Designated as Hedging Instrument [Member]
Financial Assets:
Derivatives
Financial Liabilities:
Derivatives