EMPLOYER SPONSORED BENEFIT PLANS - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Components of employer benefit cost
Service cost	$ 29	$ 40	$ 58	$ 80
Interest cost	304	428	608	857
Expected return on assets	(589)	(532)	(1,178)	(1,065)
Amortization of actuarial loss	4	0	8	2
Net periodic benefit cost (income)	(252)	(64)	(504)	(126)
Settlement loss	0	0	0	385
Total employer benefit plan cost	$ (252)	$ (64)	$ (504)	$ 259