EMPLOYEE BENEFITS - Plan Amounts Recognized in OCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Retirement Benefits [Abstract]
Net periodic pension income	$ (2)	$ (1)	$ (7)
Net actuarial (gain) loss	(31)	54	7
Amortization of prior service credit	1	1	0
Amortization of net actuarial loss	(18)	(16)	(15)
Total recognized in other comprehensive income (loss)	(48)	39	(8)
Total recognized in net periodic pension cost and other comprehensive income (loss)	$ (50)	$ 38	$ (15)