DERIVATIVE CONTRACTS AND COLLATERALIZED INDEBTEDNESS, Impact and Location of Derivative Instruments within Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Gain (loss) on equity derivative contracts, net	$ 104,927	$ (45,055)	$ (198,688)
Gain (loss) on investment securities pledged as collateral	$ (33,935)	$ 129,832	$ 313,251