OPERATING AND GEOGRAPHICAL SEGMENTS Locations of long-lived assets (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Long-lived assets	$ 201,203	$ 206,285
United States
Segment Reporting Information [Line Items]
Long-lived assets	88,965	92,466
Philippines
Segment Reporting Information [Line Items]
Long-lived assets	56,866	56,094
Germany
Segment Reporting Information [Line Items]
Long-lived assets	17,119	17,920
FRANCE
Segment Reporting Information [Line Items]
Long-lived assets	12,591	13,714
Asia-Pacific
Segment Reporting Information [Line Items]
Long-lived assets	20,338	20,237
Rest of Europe
Segment Reporting Information [Line Items]
Long-lived assets	$ 5,324	$ 5,854