GOODWILL AND INTANGIBLE ASSETS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended			6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2012	Jun. 25, 2011	Jun. 30, 2012	Jun. 25, 2011	Dec. 31, 2011	Jun. 30, 2012 Customer Relationships Y	Dec. 31, 2011 Customer Relationships Y	Jun. 30, 2012 Proprietary Software and Database Y	Dec. 31, 2011 Proprietary Software and Database Y	Jun. 30, 2012 Patents and Proprietary Technology Y	Dec. 31, 2011 Patents and Proprietary Technology Y	Jun. 30, 2012 Non-compete Agreements Y	Dec. 31, 2011 Non-compete Agreements Y
Components of amortized intangible assets
Gross Carrying Amount	$ 170,720		$ 170,720		$ 170,046	$ 156,310	$ 155,629	$ 3,066	$ 3,116	$ 9,556	$ 9,489	$ 1,788	$ 1,812
Accumulated Amortization	65,141		65,141		57,988	56,317	50,107	2,746	2,711	4,650	3,863	1,428	1,307
Weighted Average Life (in years)						13	13	6	6	8	8	6	6
Amortization expense for intangible assets	3,624	3,664	7,169	7,196
Estimated amortization expense
2012			14,185
2013			13,170
2014			12,748
2015			11,865
2016			$ 11,310