DERIVATIVE FINANCIAL INSTRUMENTS - Offsetting Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Derivative Liability [Abstract]
Gross amounts offset in the consolidated balance sheets	$ (144,309)	$ (51,973)
Deriviative Contract
Derivative Liability [Abstract]
Gross amounts of recognized liabilities	288,659	363,192
Gross amounts offset in the consolidated balance sheets	(144,309)	(78,937)
Net amounts of assets presented in the consolidated balance sheets	144,350	284,255
Derivative Liability, Fair Value, Amount Not Offset Against Collateral [Abstract]
Gross amounts not offset in the consolidated balance sheets, financial instruments	(62,460)	(78,654)
Gross amounts not offset in the consolidated balance sheets, cash collateral received	(20)	(111)
Net amount	$ 81,870	$ 205,490