Subsequent Events	12 Months Ended
Oct. 31, 2011
Subsequent Events [Abstract]
Subsequent Events	Note 14. Subsequent Events On November 30, 2011, the Company entered into a definitive agreement pursuant to which the Company, through its wholly owned subsidiary, has agreed to acquire 100% of the outstanding common stock of Magma in exchange for cash. The consummation of the acquisition is subject to certain conditions, including approval by Magma's stockholders and receipt of regulatory approvals. Subject to the receipt of all required approvals, it is currently anticipated that the closing of the acquisition will occur around the end of the second calendar quarter of 2012. The Company has agreed to pay $7.35 per share for each outstanding share of Magma common stock for a total of approximately $507 million net of cash and debt acquired. In addition, we have agreed to assume certain unvested equity awards of Magma in exchange for equity awards of the Company. In connection with our definitive agreement to acquire Magma, on December 5, 2011, December 9, 2011, and December 13, 2011, purported Magma stockholders filed shareholder class action lawsuits against Magma, Magma's directors and Synopsys. The lawsuits allege, among other things, that Magma and its directors breached their fiduciary duties to Magma's stockholders in negotiating and entering into the definitive agreement and by agreeing to sell Magma at an unfair price, pursuant to an unfair process and pursuant to unreasonable terms, and that Synopsys aided and abetted these alleged breaches of fiduciary duties. The lawsuits seek, among other things, to enjoin consummation of the acquisition and monetary damages. On December 5, 2011, plaintiff Dynetix Design Solutions, Inc. filed a patent infringement lawsuit against the Company. The lawsuit alleges, among other things, that the Company's VCS functional verification tool, and more specifically its VCS multicore technology, infringes Dynetix's United States Patent No. 6,466,898, and that such infringement is willful. The lawsuit seeks, among other things, compensatory damages and a permanent injunction.

Note 14. Subsequent Events

On November 30, 2011, the Company entered into a definitive agreement pursuant to which the Company, through its wholly owned subsidiary, has agreed to acquire 100% of the outstanding common stock of Magma in exchange for cash. The consummation of the acquisition is subject to certain conditions, including approval by Magma's stockholders and receipt of regulatory approvals. Subject to the receipt of all required approvals, it is currently anticipated that the closing of the acquisition will occur around the end of the second calendar quarter of 2012. The Company has agreed to pay $7.35 per share for each outstanding share of Magma common stock for a total of approximately $507 million net of cash and debt acquired. In addition, we have agreed to assume certain unvested equity awards of Magma in exchange for equity awards of the Company.

In connection with our definitive agreement to acquire Magma, on December 5, 2011, December 9, 2011, and December 13, 2011, purported Magma stockholders filed shareholder class action lawsuits against Magma, Magma's directors and Synopsys. The lawsuits allege, among other things, that Magma and its directors breached their fiduciary duties to Magma's stockholders in negotiating and entering into the definitive agreement and by agreeing to sell Magma at an unfair price, pursuant to an unfair process and pursuant to unreasonable terms, and that Synopsys aided and abetted these alleged breaches of fiduciary duties. The lawsuits seek, among other things, to enjoin consummation of the acquisition and monetary damages.

On December 5, 2011, plaintiff Dynetix Design Solutions, Inc. filed a patent infringement lawsuit against the Company. The lawsuit alleges, among other things, that the Company's VCS functional verification tool, and more specifically its VCS multicore technology, infringes Dynetix's United States Patent No. 6,466,898, and that such infringement is willful. The lawsuit seeks, among other things, compensatory damages and a permanent injunction.