SEGMENT INFORMATION - Revenue Per Significant Product or Service (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 26, 2022	Mar. 27, 2021
Segment Reporting Information [Line Items]
Total revenue	$ 913,929	$ 824,566
RMS
Segment Reporting Information [Line Items]
Total revenue	176,542	176,910
DSA
Segment Reporting Information [Line Items]
Total revenue	544,259	501,178
Manufacturing
Segment Reporting Information [Line Items]
Total revenue	$ 193,128	$ 146,478

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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+ Details