v3.8.0.1
PROPERTY AND EQUIPMENT, NET (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Property, Plant and Equipment [Line Items]      
Property and equipment, gross $ 18,334 $ 15,809  
Less: accumulated depreciation (7,943) (7,217)  
Total property and equipment, net 10,391 8,592  
Depreciation expense 2,159 1,867 $ 1,848
Land      
Property, Plant and Equipment [Line Items]      
Property and equipment, gross 1,435 1,435  
Building and building improvements      
Property, Plant and Equipment [Line Items]      
Property and equipment, gross 1,053 1,053  
Computer equipment and software      
Property, Plant and Equipment [Line Items]      
Property and equipment, gross 970 1,509  
Office and other equipment      
Property, Plant and Equipment [Line Items]      
Property and equipment, gross 614 430  
Instruments      
Property, Plant and Equipment [Line Items]      
Property and equipment, gross 10,666 8,228  
Sample inventory      
Property, Plant and Equipment [Line Items]      
Property and equipment, gross 1,619 1,488  
Construction in progress      
Property, Plant and Equipment [Line Items]      
Property and equipment, gross $ 1,977 $ 1,666