PENSION AND OTHER POSTRETIREMENT BENEFITS (Schedule of Net Defined Benefit Pension and Other Postretirement Costs) (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2018	Mar. 26, 2017
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Interest cost	$ 1,366	$ 1,393
Estimated return on plan assets	(1,517)	(1,313)
Amortization of net loss	301	233
Net costs	150	313
Other Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Interest cost	12	13
Estimated return on plan assets	0	0
Amortization of net loss	0	0
Net costs	$ 12	$ 13