DERIVATIVE AND HEDGING INSTRUMENTS - Gross Presentation, Effects of Offsetting, and Net Presentation of Derivatives (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Offsetting Assets:
Gross amounts of recognized assets	$ 38,111	$ 25,895
Gross amounts offset in the balance sheet	0	0
Net amounts of assets presented in the balance sheet	38,111	25,895
Financial instruments	0	0
Cash collateral received	0	0
Net amount	38,111	25,895
Offsetting Liabilities:
Gross amounts of recognized liabilities	0	0
Gross amounts offset in the balance sheet	0	0
Liabilities presented in the balance sheet	0	0
Financial instruments	0	0
Cash collateral received	0	0
Net amount	$ 0	$ 0