PENSION AND OTHER POSTRETIREMENT BENEFITS (Schedule of Economic Assumptions and Impact of Change in Discount Rate on Benefit Obligation) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 24, 2017	Dec. 31, 2017
Assumptions used to measure net pension and other postretirement cost:
Increase in Discount Rate of 0.25% - Impact on defined benefit obligation for pension benefits	$ (4,729)
Decrease in Discount Rate of 0.25% - Impact on defined benefit obligation for pension benefits	$ 4,488
Pension Benefits
Assumptions used to measure benefit obligation at end of period:
Discount rate	4.28%		3.69%
Assumptions used to measure net pension and other postretirement cost:
Discount rate	3.69%	4.32%
Expected return on plan assets	5.50%	5.50%
Other Benefits
Assumptions used to measure benefit obligation at end of period:
Discount rate	4.08%		3.39%
Assumptions used to measure net pension and other postretirement cost:
Discount rate	3.39%	3.81%