POSTRETIREMENT BENEFITS (net periodic benefit income and actuarial assumptions) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net periodic benefit income
Interest cost	$ 968	$ 1,911	$ 2,727
Expected return on plan assets	(7,498)	(7,619)	(6,957)
Amortization of prior service credit	(1,421)	(1,421)	(1,421)
Amortization of net actuarial losses	1,629	2,301	3,223
Net periodic benefit income	$ (6,322)	$ (4,828)	$ (2,428)
Participants under age 65 [Member]
Health care cost trend rates
Health care cost trend rate assumed for next year	6.90%	7.20%	7.40%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	4.50%	4.50%	4.50%
Year that the rate reaches the ultimate trend rate	2030	2030	2029
Participants age 65 and older [Member]
Health care cost trend rates
Health care cost trend rate assumed for next year	7.60%	8.00%	8.40%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	4.50%	4.50%	4.50%
Year that the rate reaches the ultimate trend rate	2030	2030	2029
Postretirement benefit plan [Member]
Net periodic benefit income
Interest cost	$ 929	$ 1,835
Actuarial assumptions
Discount rate, benefit obligation	2.61%	2.16%
Discount rate, net periodic benefit income	2.16%	3.03%	4.13%
Expected return on plan assets	5.50%	6.00%	6.25%
Pension plan [Member]
Net periodic benefit income
Interest cost	$ 39	$ 76
Actuarial assumptions
Discount rate, benefit obligation	2.26%	1.74%
Discount rate, net periodic benefit income	1.74%	2.76%	4.01%