PENSION AND OTHER POSTRETIREMENT BENEFITS (Schedule of Defined Benefit Plan Obligations and Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 27, 2020	Sep. 29, 2019	Jun. 28, 2020	Dec. 29, 2019	Jun. 30, 2019
Change in plan assets:
Fair value of plan assets, beginning of period			$ 294,589
Fair value of plan assets, end of period	$ 279,261		279,261
Pension Benefits
Change in projected benefit obligation:
Projected benefit obligation, beginning of period			369,066	$ 157,619
Interest cost	1,997	$ 1,468	6,047	4,402
Actuarial losses			30,650	20,726
Benefits paid			(9,763)	(4,564)
Curtailments and settlements			(7,083)	(8,783)
Other			22	0
Currency translation gain			(4,071)	0
Projected benefit obligation, end of period	384,868	169,400	384,868	169,400
Change in plan assets:
Fair value of plan assets, beginning of period			294,589	102,414
Actual return on plan assets			(5,343)	12,637
Contributions by employer			11,801	6,096
Benefits paid			(9,763)	(4,564)
Other			(603)	0
Currency translation loss			(4,337)	0
Fair value of plan assets, end of period	279,261	107,800	279,261	107,800
Funded status:
Unfunded benefit obligation, end of period	(105,607)		(105,607)			$ (74,477)
Amounts recognized in the Condensed Consolidated Balance Sheets at end of period:
Current liability	(3,605)		(3,605)			(14,967)
Long-term liability	(102,002)		(102,002)			(59,510)
Recognized liability	(105,607)		(105,607)			(74,477)
Amounts recognized in accumulated other comprehensive loss at end of period:
Net actuarial loss	100,579	62,431	100,579	62,431	$ 58,239	58,239	$ 54,343
Other Benefits
Change in projected benefit obligation:
Projected benefit obligation, beginning of period			1,527	1,462
Interest cost	9	13	27	39
Actuarial losses			75	130
Benefits paid			(120)	(111)
Curtailments and settlements			0	0
Other			0	0
Currency translation gain			0	0
Projected benefit obligation, end of period	1,509	1,520	1,509	1,520
Change in plan assets:
Fair value of plan assets, beginning of period			0	0
Actual return on plan assets			0	0
Contributions by employer			120	111
Benefits paid			(120)	(111)
Other			0	0
Currency translation loss			0	0
Fair value of plan assets, end of period	0	0	0	0
Funded status:
Unfunded benefit obligation, end of period	(1,509)		(1,509)			(1,527)
Amounts recognized in the Condensed Consolidated Balance Sheets at end of period:
Current liability	(156)		(156)			(158)
Long-term liability	(1,353)		(1,353)			(1,369)
Recognized liability	(1,509)		(1,509)			(1,527)
Amounts recognized in accumulated other comprehensive loss at end of period:
Net actuarial loss	$ 166	$ 95	$ 166	$ 95	$ 91	$ 91	$ (34)