DERIVATIVE FINANCIAL INSTRUMENTS - Offsetting Liabilities (Details) - Derivative Contract - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Offsetting Derivative Liabilities [Abstract]
Gross amounts of recognized liabilities	$ 338,899	$ 288,659
Gross amounts offset in the condensed consolidated balance sheets	(201,418)	(144,309)
Derivative liabilities	137,481	144,350
Gross amounts not offset in the condensed consolidated balance sheets, Financial instruments	(66,571)	(62,460)
Gross amounts not offset in the condensed consolidated balance sheets, Cash collateral received	(582)	(20)
Net amount	$ 70,329	$ 81,870