SEGMENT INFORMATION (REVENUE GEOGRAPHY) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	$ 432,213	$ 394,356
Other long-term assets	59,193		$ 68,969
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	277,676	236,967
Philippines [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	91,105	93,179
Latin America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	25,098	24,135
Europe Middle East Africa [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	16,944	16,041
Asia Pacific India[ Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	15,168	12,826
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales Revenue Services Net	$ 6,222	$ 11,208