SEGMENT INFORMATION (Details 2) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2015
Sep. 30, 2015
Jun. 30, 2015
Mar. 31, 2015
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Long-Lived Assets $ 96,663       $ 102,789       $ 96,663 $ 102,789 $ 116,721
Sales 86,960 $ 76,805 $ 82,356 $ 69,128 93,008 $ 68,924 $ 78,851 $ 70,850 315,249 311,633 329,459
United States                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Long-Lived Assets 37,607       39,656       37,607 39,656 49,270
Sales                 103,650 94,420 105,764
Other North America                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Long-Lived Assets 0       0       0 0 0
Sales                 4,820 6,474 3,693
North America                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Long-Lived Assets 37,607       39,656       37,607 39,656 49,270
Sales                 108,470 100,894 109,457
England                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Long-Lived Assets 555       604       555 604 645
Sales                 12,780 13,848 21,090
Germany                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Long-Lived Assets 1,388       1,741       1,388 1,741 1,943
Sales                 34,830 46,543 40,277
Switzerland                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Long-Lived Assets 30,322       31,524       30,322 31,524 37,055
Sales                 7,613 6,834 6,063
Other Europe                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Long-Lived Assets 74       107       74 107 143
Sales                 42,046 35,838 32,696
Europe                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Long-Lived Assets 32,339       33,976       32,339 33,976 39,786
Sales                 97,269 103,063 100,126
China                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Long-Lived Assets 10,515       11,543       10,515 11,543 12,468
Sales                 92,727 88,933 96,532
Taiwan                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Long-Lived Assets 13,453       14,603       13,453 14,603 15,197
Sales                 3,772 4,296 4,541
Other Asia                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Long-Lived Assets 2,749       3,011       2,749 3,011 0
Sales                 13,011 14,447 18,803
Asia                      
Revenues from External Customers and Long-Lived Assets [Line Items]                      
Long-Lived Assets $ 26,717       $ 29,157       26,717 29,157 27,665
Sales                 $ 109,510 $ 107,676 $ 119,876