PENSION AND POSTRETIREMENT BENEFIT PLANS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Non-current pension liabilities	$ 403		$ 403		$ 456
Defined contribution plan expense	47	$ 52
Pension Benefits [Member]
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Service cost - benefits earned during the period	7	6	14	$ 12
Interest cost on projected benefit obligation	50	46	96	94
Expected return on plan assets	(109)	(101)	(218)	(204)
Amortization of prior service credits	(1)	(1)	(2)	(2)
Amortization of net actuarial (gain)/loss	19	20	40	41
Curtailments and settlements	38	36	69	69
Net periodic benefit cost/(credit)	$ 4	$ 6	$ (1)	$ 10