SUPPLEMENTAL EXECUTIVE RETIREMENT PLAN - Components of Net Periodic Pension Cost (Details) - Supplemental Executive Retirement Plan [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Components of net periodic pension cost [Abstract]
Service cost	$ 288	$ 325
Interest cost	403	262
Amortization of prior service cost	399	421
Amortization of loss	411	118
Total net periodic benefit cost	$ 1,501	$ 1,126