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. 24, 2017	Sep. 25, 2016	Sep. 24, 2017	Sep. 25, 2016
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Interest cost	$ 1,392	$ 1,396	$ 4,178	$ 4,189
Estimated return on plan assets	(1,314)	(1,314)	(3,940)	(3,942)
Amortization of net loss	233	165	699	494
Net costs	311	247	937	741
Other Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Interest cost	13	12	38	38
Estimated return on plan assets	0	0	0	0
Amortization of net loss	0	0	0	0
Net costs	$ 13	$ 12	$ 38	$ 38