SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN - Components of Net Periodic Pension Cost (Details) - Supplemental Executive Retirement Plan [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Components of net periodic pension cost [Abstract]
Service cost	$ 354	$ 319	$ 1,062	$ 867
Interest cost	219	166	656	452
Amortization of prior service cost	415	436	1,245	1,114
Amortization of loss	3		11
Total net periodic benefit cost	$ 991	$ 921	$ 2,974	$ 2,433