PENSION AND OTHER POSTRETIREMENT BENEFITS (Schedule of Defined Benefit Plan Obligations and Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2021	Sep. 27, 2020	Sep. 26, 2021	Sep. 27, 2020	Dec. 27, 2020	Dec. 29, 2019
Change in plan assets
Fair Value of plan assets, beginning Balance			$ 305,983
Fair Value of plan assets, end of period	$ 331,879		331,879
Pension Benefits
Change in projected benefit obligation
Projected, benefit obligation, beginning of period			404,194	$ 369,066
Interest cost	1,682	$ 1,997	4,119	6,047
Actuarial (loss) gain			(9,873)	30,650
Benefits paid			(9,792)	(9,763)
Curtailments and settlements			(4,393)	(7,083)
Prior service cost			0	22
Currency translation loss (gain)			2,169	(4,071)
Projected benefit obligation, end of period	386,424	384,868	386,424	384,868
Change in plan assets
Fair Value of plan assets, beginning Balance			305,983	294,589
Actual return on plan assets			28,325	(5,343)
Contributions by employer			10,569	11,801
Benefits paid			(9,792)	(9,763)
Curtailments and settlements			(4,393)	(7,083)
Expenses paid from assets			(279)	(603)
Currency translation gain (Loss)			1,466	(4,337)
Fair Value of plan assets, end of period	331,879	279,261	331,879	279,261
Funded status
Unfunded benefit obligation, end of period	(54,545)		(54,545)		$ (98,211)
Amounts recognized in the Condensed Consolidated Balance Sheets at end of period
Current liability	(6,775)		(6,775)		(7,510)
Long-term liability	(47,770)		(47,770)		(90,701)
Recognized liability	(54,545)		(54,545)		(98,211)
Amounts recognized in accumulated other comprehensive loss at end of period
Net Actuarial loss	62,515	100,579	62,515	100,579	95,522	$ 58,239
Other Benefits
Change in projected benefit obligation
Projected, benefit obligation, beginning of period			1,593	1,527
Interest cost	4	9	12	27
Actuarial (loss) gain			(20)	75
Benefits paid			(113)	(120)
Curtailments and settlements			0	0
Prior service cost			0	0
Currency translation loss (gain)			0	0
Projected benefit obligation, end of period	1,472	1,509	1,472	1,509
Change in plan assets
Fair Value of plan assets, beginning Balance			0	0
Actual return on plan assets			0	0
Contributions by employer			113	120
Benefits paid			(113)	(120)
Curtailments and settlements			0	0
Expenses paid from assets			0	0
Currency translation gain (Loss)			0	0
Fair Value of plan assets, end of period	0	0	0	0
Funded status
Unfunded benefit obligation, end of period	(1,472)		(1,472)		(1,593)
Amounts recognized in the Condensed Consolidated Balance Sheets at end of period
Current liability	(164)		(164)		(169)
Long-term liability	(1,308)		(1,308)		(1,424)
Recognized liability	(1,472)		(1,472)		(1,593)
Amounts recognized in accumulated other comprehensive loss at end of period
Net Actuarial loss	$ 153	$ 166	$ 153	$ 166	$ 174	$ 91