The accumulated amount of amortization of a major finite-lived intangible asset class. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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- Definition

Aggregate amount of intangible asset amortization recognized as expense during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph a(2)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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The average useful life of a major finite-lived intangible asset class. A major class is composed of intangible assets that can be grouped together because they are similar either by their nature or by their use in the operations of a company.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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- Definition

Sum of the gross carrying amounts before accumulated amortization as of the balance sheet date of all intangible assets having statutory or estimated useful lives. The aggregate gross carrying amount (including any previously recognized impairment charges) of a major finite-lived intangible asset class. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The amount of amortization expense expected to be recognized during the current fiscal year.

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The amount of amortization expense expected to be recognized during the first full fiscal year following the date of the most recent balance sheet.

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The amount of amortization expense expected to be recognized during the fourth full fiscal year following the date of the most recent balance sheet.

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The amount of amortization expense expected to be recognized during the second full fiscal year following the date of the most recent balance sheet.

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The amount of amortization expense expected to be recognized during the third full fiscal year following the date of the most recent balance sheet.

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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. 24, 2011	Sep. 25, 2010	Sep. 24, 2011	Sep. 25, 2010	Dec. 25, 2010	Sep. 24, 2011 Customer Relationships Y	Dec. 25, 2010 Customer Relationships Y	Sep. 24, 2011 Proprietary Software and Database Y	Dec. 25, 2010 Proprietary Software and Database Y	Sep. 24, 2011 Patents and Proprietary Technology Y	Dec. 25, 2010 Patents and Proprietary Technology Y	Sep. 24, 2011 Non-compete Agreements Y	Dec. 25, 2010 Non-compete Agreements Y
Components of amortized intangible assets
Gross Carrying Amount	$ 169,467		$ 169,467		$ 169,433	$ 155,651	$ 155,664	$ 2,609	$ 2,609	$ 9,524	$ 9,486	$ 1,683	$ 1,674
Accumulated Amortization	54,414		54,414		43,890	47,083	37,932	2,609	2,568	3,486	2,336	1,236	1,054
Weighted Average Life (in years)						13	13	6	6	8	8	6	6
Amortization expense for intangible assets	3,659	3,521	10,855	8,295
Estimated amortization expense
2011			14,373
2012			13,886
2013			12,992
2014			12,569
2015			$ 11,730