SEGMENT INFORMATION (SEGMENT FINANCIALS) (DETAILS) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net Revenue	$ 359,036	$ 312,796	$ 1,050,742	$ 930,311
Depreciation and amortization	16,515	16,811	47,273	51,761
Income (Loss) from Operations	15,800	12,526	63,879	46,507
Capital Expenditures	14,343	11,120	43,932	38,863
Total Assets	949,518		949,518		$ 846,304
Goodwill	166,584		166,584		129,648
Operating Segments
Segment Reporting Information [Line Items]
Net Revenue	359,131	313,165	1,051,044	931,088
Intersegment Eliminations
Segment Reporting Information [Line Items]
Net Revenue	(95)	(369)	(302)	(777)
Customer Management Services
Segment Reporting Information [Line Items]
Net Revenue	277,373	223,664	798,508	664,392
Depreciation and amortization	13,455	11,891	37,843	36,024
Income (Loss) from Operations	9,133	12,255	43,804	36,189
Capital Expenditures	12,732	8,515	36,701	29,751
Total Assets	713,377		713,377		585,679
Goodwill	79,391		79,391		42,589
Customer Management Services | Operating Segments
Segment Reporting Information [Line Items]
Net Revenue	277,373	223,742	798,527	664,647
Customer Management Services | Intersegment Eliminations
Segment Reporting Information [Line Items]
Net Revenue	0	(78)	(19)	(255)
Customer Growth Services
Segment Reporting Information [Line Items]
Net Revenue	30,829	35,301	96,890	105,713
Depreciation and amortization	717	1,561	2,249	4,943
Income (Loss) from Operations	1,564	161	6,295	4,138
Capital Expenditures	346	375	708	3,546
Total Assets	60,086		60,086		71,540
Goodwill	24,439		24,439		24,439
Customer Growth Services | Operating Segments
Segment Reporting Information [Line Items]
Net Revenue	30,829	35,301	96,890	105,713
Customer Growth Services | Intersegment Eliminations
Segment Reporting Information [Line Items]
Net Revenue	0			0
Customer Technology Services
Segment Reporting Information [Line Items]
Net Revenue	34,563	36,580	105,054	109,198
Depreciation and amortization	1,772	2,457	5,377	8,187
Income (Loss) from Operations	4,158	3,776	11,034	9,932
Capital Expenditures	1,180	1,864	6,025	4,877
Total Assets	106,372		106,372		115,537
Goodwill	40,839		40,839		41,500
Customer Technology Services | Operating Segments
Segment Reporting Information [Line Items]
Net Revenue	34,658	36,871	105,337	109,720
Customer Technology Services | Intersegment Eliminations
Segment Reporting Information [Line Items]
Net Revenue	(95)	(291)	(283)	(522)
Customer Strategy Services
Segment Reporting Information [Line Items]
Net Revenue	16,271	17,251	50,290	51,008
Depreciation and amortization	571	902	1,804	2,607
Income (Loss) from Operations	945	(3,666)	2,746	(3,752)
Capital Expenditures	85	366	498	689
Total Assets	69,683		69,683		73,548
Goodwill	21,915		21,915		$ 21,120
Customer Strategy Services | Operating Segments
Segment Reporting Information [Line Items]
Net Revenue	16,271	$ 17,251	$ 50,290	51,008
Customer Strategy Services | Intersegment Eliminations
Segment Reporting Information [Line Items]
Net Revenue	$ 0			$ 0