DERIVATIVE FINANCIAL INSTRUMENTS - Offsetting Assets (Details) - Derivative Contract - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Offsetting Derivative Assets [Abstract]
Gross amounts of recognized assets	$ 334,963	$ 420,159
Gross amounts offset in the condensed consolidated balance sheets	144,951	181,940
Net amounts of assets presented in the condensed consolidated balance sheets	190,012	238,219
Gross amounts not offset in the condensed consolidated balance sheets, Financial instruments	(5,009)	(34,328)
Gross amounts not offset in the condensed consolidated balance sheets, cash collateral received	(18,448)	(5,428)
Net amount	$ 166,555	$ 198,463