DERIVATIVES - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Derivative liability position net		$ 200
Derivative asset position net		3,700
Collateral received against obligations in net asset position		5,200
Interest rate swaps | Derivative designated as a cash flow hedge
Derivative [Line Items]
Notional amounts		240,000	$ 290,000
Interest rate swaps | Derivative designated as a cash flow hedge | Federal Home Loan Bank of New York [Member]
Derivative [Line Items]
Amounts of accumulated other comprehensive income (loss) reclassified to interest expense		$ 1,100
Interest rate swaps | Derivative designated as a cash flow hedge | Federal Home Loan Bank of New York [Member] | Forecast for next twelve months
Derivative [Line Items]
Amounts of accumulated other comprehensive income (loss) reclassified to interest expense	$ 2,100