SEGMENT INFORMATION (REVENUE GEOGRAPHY) (DETAILS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	$ 338,277	$ 312,410
Other long-term assets	57,883		$ 47,520
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	178,432	174,577
Philippines [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	85,575	84,296
Latin America
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	33,117	30,158
Europe Middle East Africa [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	15,410	16,492
Asia Pacific[ Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	7,111	5,650
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	$ 18,632	$ 1,237