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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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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GOODWILL AND INTANGIBLE ASSETS - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017	Dec. 30, 2019	Apr. 01, 2019
Finite-Lived Intangible Assets, Net [Abstract]
Amortization of intangible assets	$ 17,900	$ 20,800	$ 21,400
Indefinite-lived Intangible Assets [Line Items]
Amortization of intangible assets	17,900	20,800	21,400
Goodwill [Line Items]
Goodwill	237,498	237,287	$ 226,694
SIMOS
Goodwill [Line Items]
Reporting unit, percentage of fair value in excess of carrying amount					10.00%
Goodwill	35,000
Staff Management SMX
Goodwill [Line Items]
Reporting unit, percentage of fair value in excess of carrying amount					48.00%
Subsequent Event [Member] \| SIMOS
Goodwill [Line Items]
Reporting unit, percentage of fair value in excess of carrying amount				7.00%
Trade name/trademarks
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived trade name/trademarks	$ 6,000	$ 6,000