RESTRUCTURING AND INTEGRATION COSTS - Narrative (Details) - Restructuring and Integration-Related Costs - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cost-rationalization and integration initiatives
Remaining restructuring liabilities	$ 27
Restructuring costs	22	$ 52	$ 132
Severance costs	11	16	22
Facility closure costs	10	20	19
Other costs	1		1
Restructuring payments	$ 33	85	121
Integration consulting, duplicate labor, transition service, and other		$ 16	$ 90