PENSION AND OTHER POSTRETIREMENT BENEFITS (Schedule of Defined Benefit Plan Obligations and Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 27, 2020	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017
Change in plan assets:
Fair value of plan assets, beginning of year	$ 294,589
Fair value of plan assets, end of year	305,983	$ 294,589
Pension Benefits
Change in projected benefit obligation:
Projected benefit obligation, beginning of year	369,066	157,619
Interest cost	8,102	6,673	$ 5,463
Actuarial losses	38,822	20,729
Benefits paid	(13,745)	(8,288)
Curtailments and settlements	(8,226)	(10,076)
Prior service cost	20	8
Tulip acquisition	0	198,417
Currency translation loss	10,155	3,984
Projected benefit obligation, end of year	404,194	369,066	157,619
Change in plan assets:
Fair value of plan assets, beginning of year	294,589	102,414
Actual return on plan assets	12,672	18,904
Contributions by employer	14,774	8,295
Benefits paid	(13,745)	(8,288)
Curtailments and settlements	(8,226)	(10,076)
Expenses paid from assets	(715)	(70)
Tulip acquisition	0	179,702
Currency translation gain	6,634	3,708
Fair value of plan assets, end of year	305,983	294,589	102,414
Funded status:
Unfunded benefit obligation, end of year	(98,211)	(74,477)
Amounts recognized in the Consolidated Balance Sheets as of end of year:
Current liability	(7,510)	(14,967)
Long-term liability	(90,701)	(59,510)
Recognized liability	(98,211)	(74,477)
Amounts recognized in accumulated other comprehensive loss at end of year:
Net actuarial loss	95,522	58,239	54,343	$ 54,235
Other Benefits
Change in projected benefit obligation:
Projected benefit obligation, beginning of year	1,527	1,462
Interest cost	36	52
Actuarial losses	90	132
Benefits paid	0	0
Curtailments and settlements	(60)	(119)
Prior service cost	0	0
Tulip acquisition	0	0
Currency translation loss	0	0
Projected benefit obligation, end of year	1,593	1,527	1,462
Change in plan assets:
Fair value of plan assets, beginning of year	0	0
Actual return on plan assets	0	0
Contributions by employer	60	119
Benefits paid	0	0
Curtailments and settlements	(60)	(119)
Expenses paid from assets	0	0
Tulip acquisition	0	0
Currency translation gain	0	0
Fair value of plan assets, end of year	0	0	0
Funded status:
Unfunded benefit obligation, end of year	(1,593)	(1,527)
Amounts recognized in the Consolidated Balance Sheets as of end of year:
Current liability	(169)	(158)
Long-term liability	(1,424)	(1,369)
Recognized liability	(1,593)	(1,527)
Amounts recognized in accumulated other comprehensive loss at end of year:
Net actuarial loss	$ 174	$ 91	$ (34)	$ 35