DEBT - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 3,019
Ending balance	2,759
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(21)	$ (6)
Other comprehensive loss before reclassifications	(24)	(3)
Reclassification to Income Statement	0	0
Net other comprehensive loss	(24)	(3)
Ending balance	$ (45)	$ (9)