GOODWILL AND INTANGIBLE ASSETS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 28, 2013	Dec. 29, 2012	Dec. 31, 2011
Components of amortized intangible assets
Gross Carrying Amount	$ 194,345	$ 185,389
Accumulated Amortization	87,597	72,811
Amortization expense for intangible assets	15,233	14,332	14,833
Estimated amortization expense
2014	15,724
2015	14,817
2016	14,252
2017	14,212
2018	12,491
Customer Relationships
Components of amortized intangible assets
Gross Carrying Amount	177,495	170,556
Accumulated Amortization	76,024	62,957
Weighted Average Life	13 years	13 years
Proprietary Software and Database
Components of amortized intangible assets
Gross Carrying Amount	3,896	3,073
Accumulated Amortization	2,896	2,795
Weighted Average Life	6 years	6 years
Patents and Proprietary Technology
Components of amortized intangible assets
Gross Carrying Amount	11,334	9,953
Accumulated Amortization	7,239	5,517
Weighted Average Life	8 years	8 years
Non-compete Agreements
Components of amortized intangible assets
Gross Carrying Amount	1,620	1,807
Accumulated Amortization	$ 1,438	$ 1,542
Weighted Average Life	6 years	6 years