RESTRUCTURING ACTIVITIES (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Restructuring Cost and Reserve [Line Items]
Total restructuring charges	$ 0	$ 4	$ (3)	$ 23
Accounts Payable and Accrued Liabilities
Restructuring Cost and Reserve [Line Items]
Restructuring reserve	$ 11		11		$ 38
Cost of services
Restructuring Cost and Reserve [Line Items]
Total restructuring charges		2	(1)	9
Selling, general and administrative
Restructuring Cost and Reserve [Line Items]
Total restructuring charges		$ 2	$ (2)	$ 14