OTHER REAL ESTATE OWNED - Summary of other real estate owned net of valuation allowances (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Other Real Estate [Roll Forward]      
Balance at beginning of period $ 367 $ 1,966  
Transfer of loans at net realizable value to OREO 237 986  
Sale proceeds (1,999) (3,632)  
Net gain from sale of OREO 666 1,471 $ 842
Write-down of OREO   (424)  
Acquired balance, net 2,788    
Balance at end of period $ 2,059 $ 367 $ 1,966