PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS (Nonunion) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension and other postretirement benefit plans
Pension settlement expense		$ 89	$ 1,634
Pension settlement expense, net of tax	$ 206	66	1,213
Nonunion Defined Benefit Pension Plan
Pension and other postretirement benefit plans
Pension settlement expense	278		1,634
Pension settlement expense, net of tax	200		1,200
Lump-sum distributions	$ 3,000		$ 17,900
Supplemental Benefit Plan
Pension and other postretirement benefit plans
Benefit		700
Pension settlement expense		89
Pension settlement expense, net of tax		$ 100