Contingencies	12 Months Ended
Dec. 29, 2012
Commitments and Contingencies Disclosure [Abstract]
CONTINGENCIES	CONTINGENCIES Legal Proceedings From time to time, Cadence is involved in various disputes and litigation that arise in the ordinary course of business. These include disputes and lawsuits related to intellectual property, indemnification obligations, mergers and acquisitions, licensing, contracts, distribution arrangements and employee relations matters. At least quarterly, Cadence reviews the status of each significant matter and assesses its potential financial exposure. If the potential loss from any claim or legal proceeding is considered probable and the amount or the range of loss can be estimated, Cadence accrues a liability for the estimated loss. Legal proceedings are subject to uncertainties, and the outcomes are difficult to predict. Because of such uncertainties, accruals are based on Cadence's judgments using the best information available at the time. As additional information becomes available, Cadence reassesses the potential liability related to pending claims and litigation matters and may revise estimates. In fiscal 2008, three related complaints were filed against Cadence and certain of its former executives alleging violations of securities laws. In fiscal 2008 and 2010, several derivative complaints were filed against Cadence and certain of its current or former directors and executives, making nearly identical allegations (collectively, the "securities and derivative litigation"). In February, 2011, Cadence reached settlement with all parties to the securities and derivative litigation, subject to court approval. Cadence agreed to pay total consideration of $38.0 million, of which $22.2 million was paid by Cadence's insurance carriers. Cadence's insurers also agreed to pay plaintiffs' attorneys fees of approximately $1.8 million. In fiscal 2011 Cadence and its insurance carriers paid the total settlement amount into a settlement fund for this litigation. On April 23, 2012, the court granted final approval of the securities and derivative settlement and dismissed the cases with prejudice. Other Contingencies Cadence provides its customers with a warranty on sales of hardware products, generally for a 90-day period. Cadence did not incur any significant costs related to warranty obligations during fiscal 2012, 2011 or 2010. Cadence's product license and services agreements typically include a limited indemnification provision for claims from third parties relating to Cadence's intellectual property. If the potential loss from any indemnification claim is considered probable and the amount or the range of loss can be estimated, Cadence accrues a liability for the estimated loss. The indemnification is generally limited to the amount paid by the customer. Cadence did not incur any significant losses from indemnification claims during fiscal 2012, 2011 or 2010. Cadence had purchase obligations of $43.6 million as of December 29, 2012 that were associated with agreements or commitments for purchases of goods or services.

CONTINGENCIES

Legal Proceedings

From time to time, Cadence is involved in various disputes and litigation that arise in the ordinary course of business. These include disputes and lawsuits related to intellectual property, indemnification obligations, mergers and acquisitions, licensing, contracts, distribution arrangements and employee relations matters. At least quarterly, Cadence reviews the status of each significant matter and assesses its potential financial exposure. If the potential loss from any claim or legal proceeding is considered probable and the amount or the range of loss can be estimated, Cadence accrues a liability for the estimated loss. Legal proceedings are subject to uncertainties, and the outcomes are difficult to predict. Because of such uncertainties, accruals are based on Cadence's judgments using the best information available at the time. As additional information becomes available, Cadence reassesses the potential liability related to pending claims and litigation matters and may revise estimates.

In fiscal 2008, three related complaints were filed against Cadence and certain of its former executives alleging violations of securities laws. In fiscal 2008 and 2010, several derivative complaints were filed against Cadence and certain of its current or former directors and executives, making nearly identical allegations (collectively, the "securities and derivative litigation").

In February, 2011, Cadence reached settlement with all parties to the securities and derivative litigation, subject to court approval. Cadence agreed to pay total consideration of $38.0 million, of which $22.2 million was paid by Cadence's insurance carriers. Cadence's insurers also agreed to pay plaintiffs' attorneys fees of approximately $1.8 million. In fiscal 2011 Cadence and its insurance carriers paid the total settlement amount into a settlement fund for this litigation. On April 23, 2012, the court granted final approval of the securities and derivative settlement and dismissed the cases with prejudice.

Other Contingencies

Cadence provides its customers with a warranty on sales of hardware products, generally for a 90-day period. Cadence did not incur any significant costs related to warranty obligations during fiscal 2012, 2011 or 2010.

Cadence's product license and services agreements typically include a limited indemnification provision for claims from third parties relating to Cadence's intellectual property. If the potential loss from any indemnification claim is considered probable and the amount or the range of loss can be estimated, Cadence accrues a liability for the estimated loss. The indemnification is generally limited to the amount paid by the customer. Cadence did not incur any significant losses from indemnification claims during fiscal 2012, 2011 or 2010.

Cadence had purchase obligations of $43.6 million as of December 29, 2012 that were associated with agreements or commitments for purchases of goods or services.