PENSION AND OTHER POSTRETIREMENT BENEFITS (Schedule of Economic Assumptions) (Details)	12 Months Ended
	Dec. 27, 2015	Dec. 28, 2014	Dec. 29, 2013
Pension Benefits [Member]
Benefit obligation:
Discount rate	4.47%	4.22%	4.95%
Net pension and other postretirement cost:
Discount rate	4.22%	4.95%	4.22%
Expected return on plan assets	5.50%	6.00%	6.00%
Other Benefits [Member]
Benefit obligation:
Discount rate	4.47%	4.22%	4.95%
Net pension and other postretirement cost:
Discount rate	4.22%	4.95%	4.22%