Commitments and Contingencies	9 Months Ended
Sep. 26, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies (Text Block)	Commitments and Contingencies Indemnification and Product Warranty We indemnify certain customers, distributors, suppliers, and subcontractors for attorney's fees and damages and costs awarded against these parties in certain circumstances in which our products are alleged to infringe third party intellectual property rights, including patents, trade secrets, trademarks or copyrights. We cannot estimate the amount of potential future payments, if any, that we might be required to make as a result of these agreements. To date, we have not paid any claim or been required to defend any action related to our indemnification obligations, and, accordingly, we have not accrued any amounts for such indemnification obligations. However, we may record charges in the future as a result of these indemnification obligations. We generally warrant our devices for one year against defects in materials, workmanship and material non-conformance to our specifications. We accrue for known warranty issues if a loss is probable and can be reasonably estimated, and accrue for estimated but unidentified issues based on historical activity. If there is a material increase in customer claims compared with our historical experience or if the costs of servicing warranty claims are greater than expected, we may record a charge against cost of sales. Warranty expense was not significant for any period presented in our consolidated statements of comprehensive income. Purchase Obligations We depend entirely upon subcontractors to manufacture our silicon wafers and provide assembly and test services. Due to lengthy subcontractor lead times, we must order these materials and services from these subcontractors well in advance, and we are obligated to pay for the materials and services once they are completed. As of September 26, 2014, we had approximately $143.0 million of outstanding purchase commitments to such subcontractors. We expect to receive and pay for these materials and services over the next six months. Operating Leases We lease facilities under non-cancelable lease agreements expiring at various times through 2024. There have been no significant changes to our operating lease obligations since December 31, 2013. Legal Proceedings On July 17, 2014, PLL Technologies, Inc. (PTI) filed a patent infringement lawsuit against Altera and three additional defendants in the United States District Court for the District of Delaware seeking unspecified damages, interest, costs, and fees. On October 1, 2014, PTI amended its complaint, and on October 20, 2014, Altera answered the complaint, denying the patents are valid and denying infringement. Because the case is at a very early stage, we cannot determine at this time whether any loss has been incurred by Altera nor can we reasonably estimate any potential loss or range of potential loss. On June 20, 2014, Altera filed an action in the United States District Court for the Northern District of California against PACT XPP Technologies, AG (“PACT”), for a declaratory judgment of non-infringement and invalidity relating to several patents that PACT has asserted against us. On October 8, 2014, PACT answered the complaint and asserted counterclaims that Altera infringes various patents owned by PACT. Because the case is at a very early stage, we cannot determine at this time whether any loss has been incurred by Altera nor can we reasonably estimate any potential loss or range of potential loss. We file income tax returns with the Internal Revenue Service (“IRS”) and in various United States ("U.S.") states and foreign jurisdictions. On December 8, 2011 and January 23, 2012, the IRS issued Statutory Notices of Deficiency (the “Notices”) determining, respectively, additional taxes for 2002 through 2004 of $19.8 million and additional taxes for 2005 through 2007 of $21.4 million, excluding interest. The IRS’s determinations relate primarily to inter-company transactions, computational adjustments to the R&D credit and reductions to the benefits of tax credit carry backs and carry forwards. We deposited $18.0 million as a cash bond with the IRS in 2008, and converted this amount to tax payments in March 2012. On March 6, 2012 and April 20, 2012, we filed petitions challenging the Notices in the U.S. Tax Court. The petitions request redetermination of the deficiencies produced by the IRS’s adjustments. The IRS has filed responses to our petitions, in which the IRS conceded the R&D credit adjustment for 2004. The Tax Court has consolidated the two cases and a judge has been assigned. The federal statute of limitations for the 2002 and 2003 tax years has expired, and the ongoing Tax Court litigation concerns only the 2004 through 2007 years. On January 31, 2013, the IRS conceded one of the adjustments at issue in the litigation for the 2004 through 2007 tax years. The conceded adjustment related to certain inter-company services transactions. The concession only impacted our 2007 tax year. As a result of this concession, we recognized a tax and interest benefit of $6.8 million in 2013 due to the release of certain tax reserves. Altera and the IRS have filed cross motions for partial summary judgment on the largest adjustment still at issue, which is related to the treatment of stock-based compensation in an inter-company cost-sharing transaction. As part of the partial motion for summary judgment process, both sides filed briefs on May 28, 2013, July 25, 2013 and September 9, 2013. We expect to present additional legal arguments related to certain affirmative adjustments raised by Altera in the litigation. The parties have filed a series of Joint Status Reports with the court addressing these affirmative adjustments. The parties presented oral arguments on the partial summary judgment issue to the Tax Court on July 24, 2014. We believe we have made adequate tax payments or accrued adequate amounts for our tax liabilities for 2004 through 2007 and that the outcome of the above matters will not have a material adverse effect on our consolidated operating results or financial position. On April 19, 2013, the IRS notified us that we would be audited for each of the 2010 and 2011 tax years. We believe we have made adequate tax payments or accrued adequate amounts for our tax liabilities for 2010 and 2011 and that the outcome of the audit will not have a material adverse effect on our consolidated operating results or financial position.

Commitments and Contingencies

Indemnification and Product Warranty

We indemnify certain customers, distributors, suppliers, and subcontractors for attorney's fees and damages and costs awarded against these parties in certain circumstances in which our products are alleged to infringe third party intellectual property rights, including patents, trade secrets, trademarks or copyrights. We cannot estimate the amount of potential future payments, if any, that we might be required to make as a result of these agreements. To date, we have not paid any claim or been required to defend any action related to our indemnification obligations, and, accordingly, we have not accrued any amounts for such indemnification obligations. However, we may record charges in the future as a result of these indemnification obligations.

We generally warrant our devices for one year against defects in materials, workmanship and material non-conformance to our specifications. We accrue for known warranty issues if a loss is probable and can be reasonably estimated, and accrue for estimated but unidentified issues based on historical activity. If there is a material increase in customer claims compared with our historical experience or if the costs of servicing warranty claims are greater than expected, we may record a charge against cost of sales. Warranty expense was not significant for any period presented in our consolidated statements of comprehensive income.

Purchase Obligations

We depend entirely upon subcontractors to manufacture our silicon wafers and provide assembly and test services. Due to lengthy subcontractor lead times, we must order these materials and services from these subcontractors well in advance, and we are obligated to pay for the materials and services once they are completed. As of September 26, 2014, we had approximately $143.0 million of outstanding purchase commitments to such subcontractors. We expect to receive and pay for these materials and services over the next six months.

Operating Leases

We lease facilities under non-cancelable lease agreements expiring at various times through 2024. There have been no significant changes to our operating lease obligations since December 31, 2013.

Legal Proceedings

On July 17, 2014, PLL Technologies, Inc. (PTI) filed a patent infringement lawsuit against Altera and three additional defendants in the United States District Court for the District of Delaware seeking unspecified damages, interest, costs, and fees. On October 1, 2014, PTI amended its complaint, and on October 20, 2014, Altera answered the complaint, denying the patents are valid and denying infringement. Because the case is at a very early stage, we cannot determine at this time whether any loss has been incurred by Altera nor can we reasonably estimate any potential loss or range of potential loss.

On June 20, 2014, Altera filed an action in the United States District Court for the Northern District of California against PACT XPP Technologies, AG (“PACT”), for a declaratory judgment of non-infringement and invalidity relating to several patents that PACT has asserted against us. On October 8, 2014, PACT answered the complaint and asserted counterclaims that Altera infringes various patents owned by PACT. Because the case is at a very early stage, we cannot determine at this time whether any loss has been incurred by Altera nor can we reasonably estimate any potential loss or range of potential loss.

We file income tax returns with the Internal Revenue Service (“IRS”) and in various United States ("U.S.") states and foreign jurisdictions. On December 8, 2011 and January 23, 2012, the IRS issued Statutory Notices of Deficiency (the “Notices”) determining, respectively, additional taxes for 2002 through 2004 of $19.8 million and additional taxes for 2005 through 2007 of $21.4 million, excluding interest. The IRS’s determinations relate primarily to inter-company transactions, computational adjustments to the R&D credit and reductions to the benefits of tax credit carry backs and carry forwards. We deposited $18.0 million as a cash bond with the IRS in 2008, and converted this amount to tax payments in March 2012. On March 6, 2012 and April 20, 2012, we filed petitions challenging the Notices in the U.S. Tax Court. The petitions request redetermination of the deficiencies produced by the IRS’s adjustments. The IRS has filed responses to our petitions, in which the IRS conceded the R&D credit adjustment for 2004. The Tax Court has consolidated the two cases and a judge has been assigned. The federal statute of limitations for the 2002 and 2003 tax years has expired, and the ongoing Tax Court litigation concerns only the 2004 through 2007 years.

On January 31, 2013, the IRS conceded one of the adjustments at issue in the litigation for the 2004 through 2007 tax years. The conceded adjustment related to certain inter-company services transactions. The concession only impacted our 2007 tax year. As a result of this concession, we recognized a tax and interest benefit of $6.8 million in 2013 due to the release of certain tax reserves. Altera and the IRS have filed cross motions for partial summary judgment on the largest adjustment still at issue, which is related to the treatment of stock-based compensation in an inter-company cost-sharing transaction. As part of the partial motion for summary judgment process, both sides filed briefs on May 28, 2013, July 25, 2013 and September 9, 2013. We expect to present additional legal arguments related to certain affirmative adjustments raised by Altera in the litigation. The parties have filed a series of Joint Status Reports with the court addressing these affirmative adjustments. The parties presented oral arguments on the partial summary judgment issue to the Tax Court on July 24, 2014. We believe we have made adequate tax payments or accrued adequate amounts for our tax liabilities for 2004 through 2007 and that the outcome of the above matters will not have a material adverse effect on our consolidated operating results or financial position.

On April 19, 2013, the IRS notified us that we would be audited for each of the 2010 and 2011 tax years. We believe we have made adequate tax payments or accrued adequate amounts for our tax liabilities for 2010 and 2011 and that the outcome of the audit will not have a material adverse effect on our consolidated operating results or financial position.