GOODWILL AND INTANGIBLE ASSETS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Dec. 25, 2010
Components of amortized intangible assets
Gross Carrying Amount	$ 185,389	$ 170,046
Accumulated Amortization	72,811	57,988
Amortization expense for intangible assets	14,332	14,833	11,873
Estimated amortization expense
2013	14,909
2014	14,480
2015	13,581
2016	13,008
2017	12,998
Customer Relationships
Components of amortized intangible assets
Gross Carrying Amount	170,556	155,629
Accumulated Amortization	62,957	50,107
Weighted Average Life (in years)	13	13
Proprietary Software and Database
Components of amortized intangible assets
Gross Carrying Amount	3,073	3,116
Accumulated Amortization	2,795	2,711
Weighted Average Life (in years)	6	6
Patents and Proprietary Technology
Components of amortized intangible assets
Gross Carrying Amount	9,953	9,489
Accumulated Amortization	5,517	3,863
Weighted Average Life (in years)	8	8
Non-compete Agreements
Components of amortized intangible assets
Gross Carrying Amount	1,807	1,812
Accumulated Amortization	$ 1,542	$ 1,307
Weighted Average Life (in years)	6	6