PENSION AND OTHER POSTRETIREMENT BENEFITS (Schedule of Net Periodic Benefit Cost (Income)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2018	Dec. 31, 2017	Dec. 25, 2016
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Interest cost	$ 5,463	$ 5,571	$ 5,585
Estimated return on plan assets	(6,065)	(5,254)	(5,256)
Settlement loss (gain)	0	0	2,064
Amortization of net loss	1,203	932	659
Net cost	601	1,249	3,052
Other Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Interest cost	46	51	51
Estimated return on plan assets	0	0	0
Settlement loss (gain)	(3)	2	(2)
Amortization of net loss	0	0	0
Net cost	$ 43	$ 53	$ 49