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Acquisitions.

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Business acquisition contingent consideration at fair value interest accretion.

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Allocation of goodwill not expected to be tax deductible in Business Acquisition purchase price.

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Business Acquisition Purchase Price Allocation Intangible.

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Business Combination Asset Purchase Contingent Consideration Maximum Potential Cash Payment.

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Business Combination Asset Purchase Contingent Consideration Maximum Potential Expense In Future Period.

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Business combination contingent consideration arrangements maximum potential goodwill.

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Business Combination Cost Expensed

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Business Combination Separately Recognized Transactions Additional Disclosures Acquisition Costs Unpaid Amount.

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Period over which consideration may be paid.

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Time of certain financial measures subsequent to the consummation of the acquisition related to contingent consideration.

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The calculated weighted-average amortization period of a major class of finite-lived intangible assets acquired during the current period either individually or as part of a group of assets (in either an asset acquisition or business combination). 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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Fair value, as of the acquisition date, of potential payments under the contingent consideration arrangement including cash and shares.

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Amount of cash paid to acquire the entity.

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Amount of goodwill arising from a business combination, which is the excess of the cost of the acquired entity over the amounts assigned to assets acquired and liabilities assumed.

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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For transactions that are recognized separately from the acquisition of assets and assumptions of liabilities in the business combination, such as related to pre-existing relationships with the acquiree, this element represents the disclosure of the amount of acquisition related costs.

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Acquisitions (Details) (USD $)	9 Months Ended		3 Months Ended	9 Months Ended		12 Months Ended		9 Months Ended
Acquisitions (Details) (USD $)	Oct. 01, 2011	Jan. 01, 2011	Oct. 02, 2010 Denali Software Inc [Member]	Oct. 01, 2011 Denali Software Inc [Member]	Oct. 02, 2010 Denali Software Inc [Member]	Jan. 02, 2010 Denali Software Inc [Member]	Jun. 30, 2010 Denali Software Inc [Member]	Oct. 01, 2011 2011 Acquisitions [Member] Year
Pro forma Financial information of acquisition
Total revenue			$ 237,934,000		$ 698,831,000
Net income (loss)			131,549,000		143,057,000
Acquisitions (Textual) [Abstract]
Initial Purchase Price of Acquisition, cash paid							296,800,000	49,300,000
Goodwill associated with 2011 acquisitions								32,300,000
Intangible assets associated with 2011 acquisitions								21,600,000
Weighted average life of finite- lived intangible assets								7
Goodwill not expected to be deductible for income tax purpose								32,300,000
Maximum payments for contingent consideration arrangement								5,000,000
Time of certain financial measures subsequent to the consummation of the acquisition related to contingent consideration								3 years
Acquisition related contingent consideration at initial fair value								3,500,000
Beginning date of acquisition related contingent consideration measurement period								subsequent to October 1, 2011
Acquisition-related contingent consideration at fair value	3,745,000	966,000						3,600,000
Accretion recorded after the date of acquisition								100,000
Additional Payments deferred on the acquisition date							12,600,000
Business combination, separately recognized transactions, acquisition cost expensed				1,200,000		10,200,000
Business combination, separately recognized transactions, acquisition cost potential expense In future periods				1,200,000
Business Combination Separately Recognized Transactions Additional Disclosures Acquisition Costs Unpaid Amount				1,000,000
Maximum Amount obligated to pay by Cadence	30,700,000
Period over which consideration may be paid	55 months
Portion of amount of contingent consideration potential expense in future periods	20,800,000
Business combination contingent consideration arrangements maximum potential goodwill	$ 5,600,000