GOODWILL AND INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 27, 2015	Mar. 28, 2015	Jun. 28, 2014	Jun. 27, 2015	Jun. 28, 2014	Dec. 27, 2014
Components of amortized intangible assets
Gross Carrying Amount	$ 226,616			$ 226,616		$ 228,027
Accumulated Amortization	111,939			111,939		103,050
Amortization expense for intangible assets	4,737		$ 4,634	9,650	$ 8,737
Estimated amortization expense
2015	18,124			18,124
2016	16,322			16,322
2017	16,276			16,276
2018	14,622			14,622
2019	13,795			13,795
Customer Relationships
Components of amortized intangible assets
Gross Carrying Amount	206,053			206,053		207,509
Accumulated Amortization	96,178			$ 96,178		$ 88,538
Weighted Average Life		13 years		13 years		13 years
Proprietary Software and Database
Components of amortized intangible assets
Gross Carrying Amount	3,676			$ 3,676		$ 3,769
Accumulated Amortization	2,985			$ 2,985		$ 2,977
Weighted Average Life		8 years		8 years		8 years
Patents and Proprietary Technology
Components of amortized intangible assets
Gross Carrying Amount	13,029			$ 13,029		$ 12,394
Accumulated Amortization	9,290			$ 9,290		$ 8,537
Weighted Average Life		8 years		8 years		8 years
Other
Components of amortized intangible assets
Gross Carrying Amount	3,858			$ 3,858		$ 4,355
Accumulated Amortization	$ 3,486			$ 3,486		$ 2,998
Weighted Average Life		3 years		3 years		3 years