RESTRUCTURING AND ASSET IMPAIRMENTS - Restructuring Costs by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Segment Reporting Information [Line Items]
Restructuring costs	$ 1,580	$ 2,653	$ 10,489	$ 5,887
Unallocated corporate
Segment Reporting Information [Line Items]
Restructuring costs	36	0	36	0
RMS
Segment Reporting Information [Line Items]
Restructuring costs	(33)	381	727	1,323
DSA
Segment Reporting Information [Line Items]
Restructuring costs	1,074	1,843	7,572	2,529
Manufacturing
Segment Reporting Information [Line Items]
Restructuring costs	$ 503	$ 429	$ 2,154	$ 2,035

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration