DERIVATIVES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Derivative [Line Items]
Notional amounts	$ 918,800		$ 823,900
Derivative liability position net	0
Derivative asset position net	69,200
Collateral received against obligations in net asset position	70,800
Collateral posted in net liability position	0
Interest rate swaps | Derivative designated as a cash flow hedge
Derivative [Line Items]
Notional amounts	305,000		$ 290,000
Interest income on derivative	110	$ 556
Interest income (expenses) recorded on swap transactions	110	$ 556
Interest rate swaps | Derivative designated as a cash flow hedge | Federal Home Loan Bank of New York
Derivative [Line Items]
Reduction to interest expense	(110)
Additional reclassified estimated decrease in interest expense	$ 3,000