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. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Interest cost	$ 2,011	$ 1,467	$ 4,050	$ 2,934
Estimated return on plan assets	(3,215)	(1,349)	(6,498)	(2,698)
Settlement loss	0	1,930	0	1,930
Other	93	0	537	0
Amortization of net loss	375	328	751	656
Net costs	(736)	2,376	(1,160)	2,822
Other Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Interest cost	9	13	18	26
Estimated return on plan assets	0	0	0	0
Settlement loss	0	0	0	0
Other	0	0	0	0
Amortization of net loss	0	0	0	0
Net costs	$ 9	$ 13	$ 18	$ 26