COMMITMENTS AND CONTINGENCIES - Contingent Considerations (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Aug. 07, 2015
Contingent Consideration        
Contingent acquisition liability $ 4,019 $ 4,825 $ 4,085  
Increase (Decrease) in contingent consideration 468 $ 658 $ 1,299  
Salvaggio Teal And Associates        
Contingent Consideration        
Increase (Decrease) in contingent consideration 500      
Amount expected to be paid in second quarter of 2015 and the first quarter of 2016 related to 2014 performance 1,700      
CCI Consulting Private Limited        
Contingent Consideration        
Contingent acquisition liability 1,200      
Contingent consideration classified as current 600      
Saugatuck Technology Inc.        
Contingent Consideration        
Contingent acquisition liability 1,100     $ 986
Contingent consideration classified as current $ 200      
Amount expected to be paid in second quarter of 2015 and the first quarter of 2016 related to 2014 performance       $ 1,300