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		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017	Jun. 12, 2018	Dec. 31, 2017
Amortizable intangible assets:
Gross Carrying Amount	$ 166,610		$ 166,610			$ 171,163
Accumulated Amortization	(75,748)		(75,748)			(72,502)
Net Carrying Amount	90,862		90,862			98,661
Amortization of Intangible Assets	5,200	$ 5,400	15,600	$ 16,100
Customer relationships
Amortizable intangible assets:
Gross Carrying Amount	153,945		153,945			148,114
Accumulated Amortization	(66,537)		(66,537)			(53,801)
Net Carrying Amount	87,408		87,408			94,313
Trade names/trademarks
Amortizable intangible assets:
Gross Carrying Amount	2,865		2,865			4,149
Accumulated Amortization	(995)		(995)			(3,736)
Net Carrying Amount	1,870		1,870			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	9,800		9,800			17,500
Accumulated Amortization	(8,216)		(8,216)			(13,588)
Net Carrying Amount	$ 1,584		$ 1,584			$ 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