SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Comprehensive Income (Details) $ in Thousands	6 Months Ended
	Jun. 27, 2020 USD ($)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	$ 1,144,338
Balance, ending	1,126,835
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	(232,575)
Current-period comprehensive income (loss)	(30,981)
Balance, ending	(263,556)
Gain on Hedging Activities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	14,076
Current-period comprehensive income (loss)	11,917
Balance, ending	25,993
Defined Benefit Pension Plan
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	(94,923)
Current-period comprehensive income (loss)	0
Balance, ending	(94,923)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance, beginning	(313,422)
Current-period comprehensive income (loss)	(19,064)
Balance, ending	$ (332,486)