GOODWILL AND INTANGIBLE ASSETS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 25, 2010	Dec. 26, 2009
Components of amortized intangible assets
Gross Carrying Amount	$ 170,046	$ 169,433
Accumulated Amortization	57,988	43,890
Amortization expense for intangible assets	14,833	11,873	8,953
Estimated amortization expense
2012	14,004
2013	13,112
2014	12,687
2015	11,821
2016	11,256
Customer Relationships
Components of amortized intangible assets
Gross Carrying Amount	155,629	155,664
Accumulated Amortization	50,107	37,932
Weighted Average Life (in years)	13	13
Proprietary Software and Database
Components of amortized intangible assets
Gross Carrying Amount	3,116	2,609
Accumulated Amortization	2,711	2,568
Weighted Average Life (in years)	6	6
Patents and Proprietary Technology
Components of amortized intangible assets
Gross Carrying Amount	9,489	9,486
Accumulated Amortization	3,863	2,336
Weighted Average Life (in years)	8	8
Non-compete Agreements
Components of amortized intangible assets
Gross Carrying Amount	1,812	1,674
Accumulated Amortization	$ 1,307	$ 1,054
Weighted Average Life (in years)	6	6