ACQUISITIONS AND DIVESTITURES 2 (NARRATIVE) (Details) - USD ($) $ in Thousands		9 Months Ended
	Dec. 31, 2016	Sep. 30, 2018	Sep. 30, 2017
Business Acquisition [Line Items]
Non-cash loss on assets held-for-sale		$ 2,000	$ 3,178
Customer Growth Services [Member]
Business Acquisition [Line Items]
Non-cash loss on assets held-for-sale	$ 2,600
Customer Strategy Services [Member]
Business Acquisition [Line Items]
Non-cash loss on assets held-for-sale	$ 2,700