FAIR VALUE - Carrying Amounts and Estimated Fair Values of Other Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financial assets:
Cash and due from financial institutions	$ 28,689	$ 25,203
Interest-earning deposits in other financial institutions	126,473	96,701
Securities available for sale	317,061	284,090
Securities held to maturity	3,647	3,139
Accrued interest receivable	4,748	3,684
Recurring
Financial assets:
Securities available for sale	317,061	284,090
Derivative Asset	17,893	6,466
Financial liabilities:
Derivative Liabilities	18,104	6,831
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Financial assets:
Cash and due from financial institutions	28,689	25,203
Interest-earning deposits in other financial institutions	126,473	96,701
Equity investments	1,507	2,174
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	1	63
Derivative Asset	0	0
Financial liabilities:
Demand, savings, and insured money market accounts	1,640,546	1,410,962
Time deposits	0	0
Accrued interest payable	9	27
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	317,061	284,090
Securities held to maturity	2,892	2,094
FHLBNY and FRBNY stock	0	0
Loans, net and loans held for sale	0	0
Accrued interest receivable	862	885
Derivative Asset	17,893	6,466
Financial liabilities:
Demand, savings, and insured money market accounts	0	0
Time deposits	174,034	163,761
Accrued interest payable	245	272
Derivative Liabilities	17,893	6,466
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	662	0
Securities available for sale	0	0
Securities held to maturity	754	1,045
FHLBNY and FRBNY stock	0	0
Loans, net and loans held for sale	1,489,509	1,285,215
Accrued interest receivable	4,748	3,685
Derivative Asset	0	0
Financial liabilities:
Demand, savings, and insured money market accounts	0	0
Time deposits	0	0
Accrued interest payable	0	0
Derivative Liabilities	211	365
Recurring | Carrying Amount
Financial assets:
Cash and due from financial institutions	28,689	25,203
Interest-earning deposits in other financial institutions	126,473	96,701
Equity investments	2,169	2,174
Securities available for sale		284,090
Securities held to maturity	3,597	3,115
FHLBNY and FRBNY stock	3,150	3,099
Loans, net and loans held for sale	1,475,359	1,286,926
Accrued interest receivable	5,611	4,633
Derivative Asset	17,893	6,466
Financial liabilities:
Demand, savings, and insured money market accounts	1,640,546	1,410,962
Time deposits	170,710	161,176
Accrued interest payable	254	299
Derivative Liabilities	18,104	6,831
Recurring | Estimated Fair Value
Financial assets:
Cash and due from financial institutions	28,689	25,203
Interest-earning deposits in other financial institutions	126,473	96,701
Equity investments	2,169	2,174
Securities available for sale		284,090
Securities held to maturity	3,646	3,139
Loans, net and loans held for sale	1,489,509	1,285,215
Accrued interest receivable	5,611	4,633
Derivative Asset	17,893	6,466
Financial liabilities:
Demand, savings, and insured money market accounts	1,640,546	1,410,962
Time deposits	174,034	163,761
Accrued interest payable	254	299
Derivative Liabilities	$ 18,104	$ 6,831