ACQUISITIONS AND DIVESTITURES 4 (NARRATIVE) (Details) - USD ($) $ in Thousands			3 Months Ended				9 Months Ended
	Dec. 22, 2017	Jun. 30, 2017	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Business Acquisition [Line Items]
Gain on sale of business								$ 3,323
Impairment losses							$ 1,120
Proceeds from sale of business								391
Other nonoperating income expense			$ 989		$ 4,416		(8,786)	$ 6,573
Technology Solutions Group [Member]
Business Acquisition [Line Items]
Gain on sale of business						$ 30
Impairment losses						$ 700
Proceeds from sale of business		$ 250			141
TeleTech Spain Holdings SL [Member]
Business Acquisition [Line Items]
Other nonoperating income expense					$ 3,200
Customer Growth Services [Member]
Business Acquisition [Line Items]
Proceeds from sale of business	$ 245			$ 600
Customer Technology Services [Member] | Technology Solutions Group [Member]
Business Acquisition [Line Items]
Other nonoperating income expense			$ 588				$ 1,650