GOODWILL AND INTANGIBLE ASSETS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended			9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended
	Sep. 29, 2012	Sep. 24, 2011	Sep. 29, 2012	Sep. 24, 2011	Dec. 31, 2011	Sep. 29, 2012 Customer Relationships Y	Dec. 31, 2011 Customer Relationships Y	Sep. 29, 2012 Proprietary Software and Database Y	Dec. 31, 2011 Proprietary Software and Database Y	Sep. 29, 2012 Patents and Proprietary Technology Y	Dec. 31, 2011 Patents and Proprietary Technology Y	Sep. 29, 2012 Non-compete Agreements Y	Dec. 31, 2011 Non-compete Agreements Y
Components of amortized intangible assets
Gross Carrying Amount	$ 173,733		$ 173,733		$ 170,046	$ 159,060	$ 155,629	$ 3,077	$ 3,116	$ 9,796	$ 9,489	$ 1,800	$ 1,812
Accumulated Amortization	69,362		69,362		57,988	59,951	50,107	2,773	2,711	5,142	3,863	1,496	1,307
Weighted Average Life (in years)						13	13	6	6	8	8	6	6
Amortization expense for intangible assets	3,582	3,659	10,751	10,855
Estimated amortization expense
2012			14,324
2013			13,462
2014			13,045
2015			12,129
2016			$ 11,554