PENSION AND POSTRETIREMENT BENEFIT PLANS (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Net periodic benefit cost/(credit)	$ (4)	$ 44
Non-current pension liabilities	841		$ 725
Defined contribution plan expense	85	40
Pension Assets Transfer	381
Reversion excise tax	76	0
Pension Benefits [Member]
Pension, Postretirement And Postemployment Liabilities Statement [Line Items]
Service cost - benefits earned during the period	12	7
Interest cost on projected benefit obligation	8	44
Expected return on plan assets	(23)	(64)
Amortization of prior service credits	(1)	(1)
Amortization of net actuarial (gain)/loss	11	18
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment	2	49
Net periodic benefit cost/(credit)	9	$ 53
Non-current pension liabilities	$ 560		$ 569