PENSION AND OTHER POSTRETIREMENT BENEFITS (Schedule of Net Defined Benefit Pension and Other Postretirement Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2016	Jun. 28, 2015	Jun. 26, 2016	Jun. 28, 2015
Pension Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Interest cost	$ 1,397	$ 1,939	$ 2,793	$ 3,877
Estimated return on plan assets	(1,314)	(1,671)	(2,628)	(3,342)
Settlement loss	0	210	0	3,272
Amortization of net loss	164	178	329	357
Net costs	247	656	494	4,164
Other Benefits [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Interest cost	14	17	26	34
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	$ 14	$ 17	$ 26	$ 34