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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Components of net periodic pension cost [Abstract]
Service cost	$ 227	$ 326	$ 742	$ 976
Interest cost	403	261	1,209	785
Amortization of prior service cost	399	420	1,197	1,262
Amortization of loss	410	119	1,231	355
Total net periodic benefit cost	$ 1,439	$ 1,126	$ 4,379	$ 3,378