SEGMENT INFORMATION (REVENUE GEOGRAPHY) (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
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	$ 359,036	$ 312,796	$ 1,050,742	$ 930,311
Other long-term assets	59,628		59,628		$ 47,520
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	197,664	166,993	570,305	507,819
Philippines [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	86,938	90,692	258,360	259,898
Latin America
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	31,361	30,832	96,301	90,154
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	18,937	891	56,035	3,020
Europe Middle East Africa [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	14,892	15,604	45,555	49,100
Asia Pacific[ Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	$ 9,244	$ 7,784	$ 24,186	$ 20,320