RESTRUCTURING ACTIVITIES (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ (3)	$ 12
Accounts Payable and Accrued Liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	26		$ 38
Cost of services
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	(1)	4
Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ (2)	$ 8