Fair Value of Consideration Transferred (Detail) (USD $) In Thousands, unless otherwise specified	Aug. 01, 2012 Esterel Technologies, S.A.	Aug. 01, 2011 Apache Design Solutions, Inc.
Business Acquisition [Line Items]
Cash	$ 58,150	$ 301,306
Contingent consideration		9,501
ANSYS replacement stock options		3,170
Total consideration transferred at fair value	$ 58,200	$ 313,977

Fair value, as of the acquisition date, of potential payments under the contingent consideration arrangement including cash and shares.

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+ Details

- Definition

The acquisition-date fair value of the equity interests of the acquirer, including the number of instruments or interests issued or issuable in consideration for the business combination.

+ References+ Details

- Definition

This element represents the acquisition-date fair value of the total consideration transferred which consists of the sum of the acquisition-date fair values of the assets transferred by the acquirer, the liabilities incurred by the acquirer to former owners of the acquiree, and the equity interests issued by the acquirer.

+ References+ Details