EMPLOYEE BENEFIT PLANS - Net Periodic Costs and Other Amounts Recognized (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Net periodic pension cost:      
Service cost $ 55 $ 64 $ 560
Interest cost 775 757 859
Expected return on plan assets (989) (983) (1,153)
Amortization of unrecognized net loss 153 159 209
Net periodic (cost) benefit $ (6) $ (3) $ 475