GOODWILL AND INTANGIBLE ASSETS - Amortized Intangible Assets - (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 30, 2017
Components of amortized intangible assets
Gross Carrying Amount	$ 250,329		$ 250,329		$ 216,035
Accumulated Amortization	141,390		141,390		142,289
Amortization expense for intangible assets	3,721	$ 4,025	11,176	$ 11,792
Estimated amortization expense
2018	15,264		15,264
2019	16,081		16,081
2020	14,969		14,969
2021	12,885		12,885
2022	10,740		10,740
Customer Relationships
Components of amortized intangible assets
Gross Carrying Amount	218,492		218,492		200,810
Accumulated Amortization	130,082		$ 130,082		$ 131,062
Weighted Average Life			13 years		13 years
Patents & Proprietary Technology
Components of amortized intangible assets
Gross Carrying Amount	23,846		$ 23,846		$ 6,693
Accumulated Amortization	4,440		$ 4,440		$ 3,999
Weighted Average Life			14 years		11 years
Other
Components of amortized intangible assets
Gross Carrying Amount	7,991		$ 7,991		$ 8,532
Accumulated Amortization	$ 6,868		$ 6,868		$ 7,228
Weighted Average Life			5 years		5 years