SEGMENTS INFORMATION - Geographical Information of Long-Lived Assets Based on Physical Location (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	$ 75,962	$ 73,616
Belarus
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	47,124	46,011
Russia
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	7,853	7,203
Ukraine
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	5,847	5,610
Hungary
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	3,384	3,485
United States
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	3,013	2,618
Poland
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	2,498	2,213
China
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	1,785	1,887
India
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	1,530	1,650
Other
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	$ 2,928	$ 2,939