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REVENUES - General Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2023	Sep. 30, 2022	Sep. 29, 2023	Sep. 30, 2022	Dec. 30, 2022
Revenue
Payroll taxes, bonuses and employee benefit costs for all Company personnel	$ 23,805	$ 20,373	$ 68,606	$ 60,169
Revenue of the entity recorded in which it acts solely in the capacity of an agent			0
Retained accounts receivable	$ 14,300		$ 14,300		$ 8,500
Maximum
Revenue
Percent of revenue (as a percent)	3.00%		3.00%
Minimum
Revenue
Percent of revenue (as a percent)	2.00%		2.00%
Cost of Sales
Revenue
Payroll taxes, bonuses and employee benefit costs for all Company personnel			$ 0
Allocation of facilities costs to contract revenue			$ 0