GOODWILL AND INTANGIBLE ASSETS (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Components of amortized intangible assets
Gross Carrying Amount	$ 228,027	$ 194,345
Accumulated Amortization	103,050	87,597
Amortization expense for intangible assets	18,414us-gaap_AmortizationOfIntangibleAssets	15,233us-gaap_AmortizationOfIntangibleAssets	14,332us-gaap_AmortizationOfIntangibleAssets
Estimated amortization expense
2015	18,176
2016	16,406
2017	16,364
2018	14,703
2019	13,871
Customer Relationships
Components of amortized intangible assets
Gross Carrying Amount	207,509	177,495
Accumulated Amortization	88,538	76,024
Weighted Average Life	13 years	13 years
Proprietary Software and Database
Components of amortized intangible assets
Gross Carrying Amount	3,769	3,896
Accumulated Amortization	2,977	2,896
Weighted Average Life	8 years	6 years
Patents and Proprietary Technology
Components of amortized intangible assets
Gross Carrying Amount	12,394	11,334
Accumulated Amortization	8,537	7,239
Weighted Average Life	8 years	8 years
Non-compete Agreements
Components of amortized intangible assets
Gross Carrying Amount	4,355	1,620
Accumulated Amortization	$ 2,998	$ 1,438
Weighted Average Life	3 years	6 years

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References