PENSION AND OTHER POSTRETIREMENT BENEFITS (Schedule of Economic Assumptions and Impact of Change in Discount Rate on Benefit Obligation) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jul. 01, 2018	Jun. 25, 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	$ (4,767)
Decrease in Discount Rate of 0.25% - Impact on defined benefit obligation for pension benefits	$ 4,525
Pension Benefits
Assumptions used to measure benefit obligation at end of period:
Discount rate	4.24%		3.69%
Assumptions used to measure net pension and other postretirement cost:
Discount rate	3.69%	4.31%
Expected return on plan assets	5.50%	5.50%
Other Benefits
Assumptions used to measure benefit obligation at end of period:
Discount rate	4.02%		3.39%
Assumptions used to measure net pension and other postretirement cost:
Discount rate	3.39%	3.81%