DERIVATIVE AND HEDGING INSTRUMENTS - Gross Presentation, Effects of Offsetting, and Net Presentation of Derivatives (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Offsetting Assets:
Gross amounts of recognized assets	$ 20,940	$ 29,344
Gross amounts offset in the balance sheet, assets	0	0
Net amounts of assets presented in the balance sheet	20,940	29,344
Financial instruments, assets	(6,349)	(2,069)
Cash collateral received, assets	0	0
Net amount, assets	14,591	27,275
Offsetting Liabilities:
Gross amounts of recognized liabilities	11,926	4,529
Gross amounts offset in the balance sheet, liabilities	0	0
Liabilities presented in the balance sheet	11,926	4,529
Financial instruments, liabilities	(6,349)	(2,069)
Cash collateral received, liabilities	0	0
Net amount, liabilities	$ 5,577	$ 2,460

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