FAIR VALUE - Carrying Amounts and Estimated Fair Values of Other Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Financial assets:
Cash and due from financial institutions	$ 28,153	$ 33,040
Interest-earning deposits in other financial institutions	97,657	96,932
Equity investments	2,032	1,909
Securities available for sale	266,721	242,258
Securities held to maturity	3,857	4,858
Accrued interest receivable	3,995	3,703
Recurring
Financial assets:
Equity investments	1,198	1,075
Securities available for sale	266,721	242,258
Derivative assets	4,091	3,142
Financial liabilities:
Derivative liabilities	4,321	3,282
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets:
Cash and due from financial institutions	28,153	33,040
Interest-earning deposits in other financial institutions	97,657	96,932
Equity investments	1,198	1,075
Securities available for sale	0	0
Securities held to maturity	0	0
FHLBNY and FRBNY stock	0	0
Loans, net and loans held for sale	0	0
Accrued interest receivable	18	80
Derivative assets	0	0
Financial liabilities:
Demand, savings, and insured money market accounts	1,409,509	1,419,011
Time deposits	0	0
Accrued interest payable	41	26
Derivative liabilities	0	0
Recurring | Significant Other Observable Inputs (Level 2)
Financial assets:
Cash and due from financial institutions	0	0
Interest-earning deposits in other financial institutions	0	0
Equity investments	0	0
Securities available for sale	266,721	242,258
Securities held to maturity	1,851	1,838
FHLBNY and FRBNY stock	0	0
Loans, net and loans held for sale	0	0
Accrued interest receivable	927	697
Derivative assets	4,091	3,142
Financial liabilities:
Demand, savings, and insured money market accounts	0	0
Time deposits	157,939	150,938
Accrued interest payable	238	206
Derivative liabilities	4,091	3,142
Recurring | Significant Unobservable Inputs (Level 3)
Financial assets:
Cash and due from financial institutions	0	0
Interest-earning deposits in other financial institutions	0	0
Equity investments	0	0
Securities available for sale	0	0
Securities held to maturity	2,006	3,020
FHLBNY and FRBNY stock	0	0
Loans, net and loans held for sale	1,277,534	1,287,495
Accrued interest receivable	3,995	3,703
Derivative assets	0	0
Financial liabilities:
Demand, savings, and insured money market accounts	0	0
Time deposits	0	0
Accrued interest payable	0	0
Derivative liabilities	230	140
Recurring | Carrying Amount
Financial assets:
Cash and due from financial institutions	28,153	33,040
Interest-earning deposits in other financial institutions	97,657	96,932
Equity investments	1,198	1,075
Securities available for sale	266,721	242,258
Securities held to maturity	3,861	4,875
FHLBNY and FRBNY stock	3,143	3,138
Loans, net and loans held for sale	1,279,950	1,293,464
Accrued interest receivable	4,940	4,480
Derivative assets	4,091	3,142
Financial liabilities:
Demand, savings, and insured money market accounts	1,409,509	1,419,011
Time deposits	156,993	150,226
Accrued interest payable	279	232
Derivative liabilities	4,321	3,282
Recurring | Estimated Fair Value
Financial assets:
Cash and due from financial institutions	28,153	33,040
Interest-earning deposits in other financial institutions	97,657	96,932
Equity investments	1,198	1,075
Securities available for sale	266,721	242,258
Securities held to maturity	3,857	4,858
Loans, net and loans held for sale	1,277,534	1,287,495
Accrued interest receivable	4,940	4,480
Derivative assets	4,091	3,142
Financial liabilities:
Demand, savings, and insured money market accounts	1,409,509	1,419,011
Time deposits	157,939	150,938
Accrued interest payable	279	232
Derivative liabilities	$ 4,321	$ 3,282