FAIR VALUES - Carrying Amounts and Estimated Fair Values of Other Financial Instruments (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Financial assets:
Cash and due from financial institutions	$ 25,203,000	$ 33,040,000
Interest-earning deposits in other financial institutions	96,701,000	96,932,000
Securities available for sale	284,090,000	242,258,000
Securities held to maturity	3,115,000	4,875,000
Loans, net and loans held for sale	1,312,903,000	1,315,609,000
Accrued interest receivable	3,684,000	3,703,000
Deposits:
Time deposits	161,176,000	150,226,000
Securities sold under agreements to repurchase	0	0	$ 10,000,000
Carrying Amount
Financial assets:
Cash and due from financial institutions	25,203,000	33,040,000
Interest-earning deposits in other financial institutions	96,701,000	96,932,000
Equity investments	2,174,000	1,909,000
Securities available for sale	284,090,000	242,258,000
Securities held to maturity	3,115,000	4,875,000
FHLBNY and FRBNY stock	3,099,000	3,138,000
Loans, net and loans held for sale	1,286,926,000	1,293,464,000
Accrued interest receivable	4,633,000	4,480,000
Derivative assets	6,466,000	3,142,000
Deposits:
Demand, savings, and insured money market accounts	1,410,962,000	1,419,011,000
Time deposits	161,176,000	150,226,000
Securities sold under agreements to repurchase		0
FHLBNY overnight advances		0
FHLBNY term advances		0
Accrued interest payable	299,000	232,000
Derivative liabilities	6,831,000	3,282,000
Estimated Fair Value
Financial assets:
Cash and due from financial institutions	25,203,000	33,040,000
Interest-earning deposits in other financial institutions	96,701,000	96,932,000
Equity investments	2,174,000	1,909,000
Securities available for sale	284,090,000	242,258,000
Securities held to maturity	3,139,000	4,858,000
Loans, net and loans held for sale	1,285,215,000	1,287,495,000
Accrued interest receivable	4,633,000	4,480,000
Derivative assets	6,466,000	3,142,000
Deposits:
Demand, savings, and insured money market accounts	1,410,962,000	1,419,011,000
Time deposits	163,761,000	150,938,000
Securities sold under agreements to repurchase		0
FHLBNY overnight advances		0
FHLBNY term advances		0
Accrued interest payable	299,000	232,000
Derivative liabilities	6,831,000	3,282,000
Estimated Fair Value | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets:
Cash and due from financial institutions	25,203,000	33,040,000
Interest-earning deposits in other financial institutions	96,701,000	96,932,000
Equity investments	2,174,000	1,909,000
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	63,000	80,000
Derivative assets	0	0
Deposits:
Demand, savings, and insured money market accounts	1,410,962,000	1,419,011,000
Time deposits	0	0
Securities sold under agreements to repurchase		0
FHLBNY overnight advances		0
FHLBNY term advances		0
Accrued interest payable	27,000	26,000
Derivative liabilities	0	0
Estimated Fair Value | 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	284,090,000	242,258,000
Securities held to maturity	2,094,000	1,838,000
FHLBNY and FRBNY stock	0	0
Loans, net and loans held for sale	0	0
Accrued interest receivable	885,000	697,000
Derivative assets	6,466,000	3,142,000
Deposits:
Demand, savings, and insured money market accounts	0	0
Time deposits	163,761,000	150,938,000
Securities sold under agreements to repurchase		0
FHLBNY overnight advances		0
FHLBNY term advances		0
Accrued interest payable	272,000	206,000
Derivative liabilities		3,142,000
Estimated Fair Value | 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	1,045,000	3,020,000
FHLBNY and FRBNY stock	0	0
Loans, net and loans held for sale	1,285,215,000	1,287,495,000
Accrued interest receivable	3,685,000	3,703,000
Derivative assets	0	0
Deposits:
Demand, savings, and insured money market accounts	0	0
Time deposits	0	0
Securities sold under agreements to repurchase		0
FHLBNY overnight advances		0
FHLBNY term advances		0
Accrued interest payable	$ 0	0
Derivative liabilities		$ 140,000