SEGMENT INFORMATION (SEGMENT FINANCIALS) (DETAILS) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Gross Revenue									$ 1,195,553	$ 1,169,408	$ 1,180,743
Intersegment Sales									(2,396)	(6,427)	(1,355)
Net Revenue	318,087	296,995	289,692	288,383	295,261	286,268	288,798	292,654	1,193,157	1,162,981	1,179,388
Depreciation and amortization	12,783	11,463	11,263	10,555	10,126	10,695	10,229	10,116	46,064	41,166	44,889
Income (Loss) from Operations	32,765	25,961	19,675	22,998	25,988	27,361	6,446	18,750	101,399	78,545	93,454
Capital Expenditures									50,364	40,653	38,667
Total Assets	842,342				851,630				842,342	851,630	746,978
Goodwill	102,743				98,241				102,743	98,241	70,844
Customer Management Services [Member]
Segment Reporting Information [Line Items]
Gross Revenue									892,145	923,774	983,627
Intersegment Sales									(1,262)	0	0
Net Revenue									890,883	923,774	983,627
Depreciation and amortization									33,884	32,714	37,561
Income (Loss) from Operations									75,689	60,271	71,945
Capital Expenditures									40,007	32,736	33,931
Total Assets	554,015				588,627				554,015	588,627	567,852
Goodwill	19,819				20,288				19,819	20,288	20,594
Customer Growth Services [Member]
Segment Reporting Information [Line Items]
Gross Revenue									100,996	100,846	95,629
Intersegment Sales									0	(74)	0
Net Revenue									100,996	100,772	95,629
Depreciation and amortization									4,127	3,904	3,714
Income (Loss) from Operations									3,024	2,258	6,387
Capital Expenditures									3,421	3,983	2,346
Total Assets	86,416				54,164				86,416	54,164	56,038
Goodwill	30,128				24,439				30,128	24,439	24,439
Customer Technology Services [Member]
Segment Reporting Information [Line Items]
Gross Revenue									152,769	101,430	68,333
Intersegment Sales									(284)	(4,582)	(1,355)
Net Revenue									152,485	96,848	66,978
Depreciation and amortization									6,201	3,026	2,515
Income (Loss) from Operations									19,965	15,714	13,652
Capital Expenditures									6,450	3,390	1,842
Total Assets	157,040				152,500				157,040	152,500	78,823
Goodwill	42,709				42,153				42,709	42,153	18,516
Customer Strategy Services [Member]
Segment Reporting Information [Line Items]
Gross Revenue									49,643	43,358	33,154
Intersegment Sales									(850)	(1,771)	0
Net Revenue									48,793	41,587	33,154
Depreciation and amortization									1,852	1,522	1,099
Income (Loss) from Operations									2,721	302	1,470
Capital Expenditures									486	544	548
Total Assets	44,871				56,339				44,871	56,339	44,265
Goodwill	$ 10,087				$ 11,361				$ 10,087	$ 11,361	$ 7,295