EMPLOYER SPONSORED BENEFIT PLANS - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Components of employer benefit cost
Service cost	$ 29	$ 40
Interest cost	304	430
Expected return on assets	(589)	(533)
Amortization of actuarial loss	4	2
Net periodic benefit cost (income)	(252)	(61)
Settlement loss	0	385
Total employer benefit plan cost	$ (252)	$ 324