PENSION AND OTHER POSTRETIREMENT BENEFITS (Schedule of Net Defined Benefit Pension and Other Postretirement Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 25, 2016	Sep. 27, 2015	Sep. 25, 2016	Sep. 27, 2015
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Interest cost	$ 1,396	$ 1,938	$ 4,189	$ 5,815
Estimated return on plan assets	(1,314)	(1,671)	(3,942)	(5,013)
Settlement loss	0	357	0	3,629
Amortization of net loss	165	179	494	536
Net costs	247	803	741	4,967
Other Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Interest cost	12	16	38	50
Estimated return on plan assets	0	0	0	0
Settlement loss	0	0	0	0
Amortization of net loss	0	0	0	0
Net costs	$ 12	$ 16	$ 38	$ 50