SEGMENT DATA Capital Expenditure (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Capital expenditures	$ 24,905	$ 22,379	$ 26,654
BULGARIA
Segment Reporting Information [Line Items]
Capital expenditures	4,584	3,304	3,517
CZECH REPUBLIC
Segment Reporting Information [Line Items]
Capital expenditures	10,449	8,043	10,982
ROMANIA
Segment Reporting Information [Line Items]
Capital expenditures	6,639	6,863	5,794
Slovak Republic [Member]
Segment Reporting Information [Line Items]
Capital expenditures	1,963	1,693	2,921
Total operating segments [Member]
Segment Reporting Information [Line Items]
Capital expenditures	23,635	19,903	23,214
Corporate [Member]
Segment Reporting Information [Line Items]
Capital expenditures	$ 1,270	$ 2,476	$ 3,440