ACQUISITIONS - Sterling (Details) - USD ($)
$ in Thousands
Nov. 10, 2016
Dec. 31, 2016
Dec. 31, 2015
Business Acquisition [Line Items]      
Goodwill   $ 48,836 $ 46,519
Intangibles $ 2,300    
Sterling      
Business Acquisition [Line Items]      
Total Purchase consideration 400,000    
Consideration paid in cash 5,200    
Goodwill 2,300    
Intangibles $ 2,300    
Amortization period 20 years