SEGMENT INFORMATION (REVENUE GEOGRAPHY) (DETAILS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	$ 353,429	$ 305,105	$ 691,706	$ 617,515
Other long-term assets	59,495		59,495		$ 47,520
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	194,209	166,249	372,641	340,827
Philippines [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	85,847	84,910	171,422	169,204
Latin America
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	31,823	29,164	64,940	59,322
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	18,466	892	37,098	2,129
Europe Middle East Africa [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	15,253	17,004	30,663	33,497
Asia Pacific[ Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	$ 7,831	$ 6,886	$ 14,942	$ 12,536