PRODUCT WARRANTY (Tables)
 12 Months Ended
Dec. 31, 2014
PRODUCT WARRANTY [Abstract]  
Schedule of product warranty
Total  
Product warranty  
Balance as of December 31, 2011 300  
Warranty accrued 284  
Utilized     (118 )
Balance as of December 31, 2012     466  
Warranty accrued     989  
Utilized     (237 )
Balance as of December 31, 2013     1,218  
Warranty accrued     2,193  
Utilized     (226 )
Balance as of December 31, 2014     3,185