FAIR VALUE MEASUREMENTS (Additional Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount	$ 0	$ 0
Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period, fair value measurements using Level 3 inputs	1,237	943
Loss included in earnings 2	(8)	(1)
Purchases	1,717	1,552
Settlements	(2,269)	(1,257)
Balance at end of period, fair value measurements using Level 3 inputs	$ 677	$ 1,237