DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Schedule of Derivative Activities Recorded in the Statement of Consolidated Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Realized gain (loss):
Unrealized loss	$ (59)	$ 0	$ 0
Not Designated as Hedging Instrument
Realized gain (loss):
Derivative settlements, realized gain	24	0	0
Amortization of put premium, realized loss	(100)	0	0
Unrealized loss	(59)	0	0
Derivative instrument gain (losses), net	$ (135)	$ 0	$ 0