RESTRUCTURING AND ASSET IMPAIRMENTS - Severance and Retention Costs by Reportable Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2021	Dec. 26, 2020	Dec. 28, 2019
Segment Reporting Information [Line Items]
Restructuring costs	$ 6,856	$ 12,594	$ 13,839
Total reportable segments | RMS
Segment Reporting Information [Line Items]
Restructuring costs	7	845	3,110
Total reportable segments | DSA
Segment Reporting Information [Line Items]
Restructuring costs	3,114	8,605	7,307
Total reportable segments | Manufacturing
Segment Reporting Information [Line Items]
Restructuring costs	3,663	2,733	3,032
Unallocated corporate
Segment Reporting Information [Line Items]
Restructuring costs	$ 72	$ 411	$ 390