SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Comprehensive Income (Details) $ in Thousands	3 Months Ended
	Mar. 28, 2020 USD ($)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at the beginning of the period	$ (313,422)
Balance at the end of the period	(347,868)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at the beginning of the period	(232,575)
Current-period comprehensive income (loss)	(49,886)
Balance at the end of the period	(282,461)
Gain/(Loss) on Hedging Activities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at the beginning of the period	14,076
Current-period comprehensive income (loss)	15,440
Balance at the end of the period	29,516
Defined Benefit Pension Plan
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at the beginning of the period	(94,923)
Current-period comprehensive income (loss)	0
Balance at the end of the period	(94,923)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance at the beginning of the period	(313,422)
Current-period comprehensive income (loss)	(34,446)
Balance at the end of the period	$ (347,868)