GOODWILL AND INTANGIBLE ASSETS - Amortized Intangible Assets - (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 28, 2020	Mar. 30, 2019	Dec. 28, 2019
Components of amortized intangible assets
Gross Carrying Amount	$ 256,666		$ 269,748
Accumulated Amortization	151,204		163,113
Amortization expense for intangible assets	4,593	$ 4,390
Estimated amortization expense
2020	17,446
2021	15,516
2022	13,462
2023	11,830
2024	9,923
Customer Relationships
Components of amortized intangible assets
Gross Carrying Amount	224,920		237,626
Accumulated Amortization	$ 137,988		149,720
Weighted Average Life	13 years	13 years
Patents & Proprietary Technology
Components of amortized intangible assets
Gross Carrying Amount	$ 23,867		24,068
Accumulated Amortization	$ 6,718		6,358
Weighted Average Life	13 years	14 years
Other
Components of amortized intangible assets
Gross Carrying Amount	$ 7,879		8,054
Accumulated Amortization	$ 6,498		$ 7,035
Weighted Average Life	4 years	5 years

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized in the remainder of the fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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