RESTRUCTURING CHARGES AND IMPAIRMENT LOSSES (LIABILITY CLASSIFICATION TABLE) (DETAILS) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restructuring Cost and Reserve [Line Items]
Reduction in force									$ 3,400	$ 1,814	$ 3,336
Facility exit charges										992		$ 14
Restructuring charges, net	$ 502	$ 3,688	$ 114	$ 88	$ 185	$ 622	$ 198	$ 809	4,392	1,814	3,350
Customer Management Services
Restructuring Cost and Reserve [Line Items]
Reduction in force									2,837	1,482	2,182
Facility exit charges										959	0	14
Customer Growth Services
Restructuring Cost and Reserve [Line Items]
Reduction in force									147	22	56
Facility exit charges										0	0	0
Customer Technology Services
Restructuring Cost and Reserve [Line Items]
Reduction in force									324	13	709
Facility exit charges										33	0	0
Customer Strategy Services
Restructuring Cost and Reserve [Line Items]
Reduction in force									$ 92	297	389
Facility exit charges										$ 0	$ 0	$ 0