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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GOODWILL AND INTANGIBLE ASSETS - Intangible Assets Other Than Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2018	Jul. 02, 2017	Jul. 01, 2018	Jul. 02, 2017	Jun. 12, 2018	Dec. 31, 2017
Amortizable intangible assets:
Gross Carrying Amount	$ 172,696		$ 172,696			$ 171,163
Accumulated Amortization	(76,621)		(76,621)			(72,502)
Net Carrying Amount	96,075		96,075			98,661
Amortization of Intangible Assets	5,200	$ 5,300	10,400	$ 10,700
Customer relationships
Amortizable intangible assets:
Gross Carrying Amount	154,060		154,060			148,114
Accumulated Amortization	(62,048)		(62,048)			(53,801)
Net Carrying Amount	92,012		92,012			94,313
Trade names/trademarks
Amortizable intangible assets:
Gross Carrying Amount	2,865		2,865			4,149
Accumulated Amortization	(889)		(889)			(3,736)
Net Carrying Amount	1,976		1,976			413
Non-compete agreements
Amortizable intangible assets:
Gross Carrying Amount	0		0			1,400
Accumulated Amortization	0		0			(1,377)
Net Carrying Amount	0		0			23
Technologies
Amortizable intangible assets:
Gross Carrying Amount	15,771		15,771			17,500
Accumulated Amortization	(13,684)		(13,684)			(13,588)
Net Carrying Amount	$ 2,087		$ 2,087			$ 3,912
TMP
Amortizable intangible assets:
Estimated fair value					$ 8,024
TMP \| Customer relationships
Amortizable intangible assets:
Estimated fair value					6,286
TMP \| Trade names/trademarks
Amortizable intangible assets:
Estimated fair value					$ 1,738