OTHER COMPREHENSIVE INCOME - AOCI Changes (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Summary of the AOCI balances, net of tax      
Balance at beginning of period $ 576,547 $ 558,731 $ 542,793
Current Year Change (1,362) (2,266) 1,194
Balance at end of period 604,406 576,547 558,731
Accumulated Other Comprehensive Income      
Summary of the AOCI balances, net of tax      
Balance at beginning of period 2,049 4,315 3,121
Current Year Change (1,362) (2,266) 1,194
Balance at end of period 687 2,049 4,315
Unrealized gain on securities available for sale      
Summary of the AOCI balances, net of tax      
Balance at beginning of period 1,727 3,839  
Current Year Change (1,490) (2,112)  
Balance at end of period 237 1,727 3,839
Unrealized gain on security available for sale for which a portion of an other-than-temporary impairment has been recognized in earnings      
Summary of the AOCI balances, net of tax      
Balance at beginning of period 712 792  
Current Year Change (6) (80)  
Balance at end of period 706 712 792
Unrealized loss on cash flow hedge      
Summary of the AOCI balances, net of tax      
Balance at beginning of period (390) (316)  
Current Year Change 134 (74)  
Balance at end of period $ (256) $ (390) $ (316)