Significant Accounting Policies (Policy)	3 Months Ended
Significant Accounting Policies (Policy)	Mar. 31, 2014
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Significant estimates made by management include the provision for doubtful accounts receivable, the provision to reduce obsolete or excess inventory to market, the provision for estimated returns, as well as sales allowances, the assumptions used in the valuation of stock-based awards, the assumptions used in the discounted cash flows to mark certain of its investments to market, the valuation of the Company’s goodwill, net realizable value of product related and other intangible assets, the provision for income taxes and the amortization and depreciation periods for intangible and long-lived assets. While the Company believes that such estimates are fair when considered in conjunction with the condensed consolidated financial position and results of operations taken as a whole, the actual amounts of such items, when known, will vary from these estimates.
Investments	Investments Short-term and long-term investments as of March 31, 2014 and December 31, 2013 primarily consist of agency securities, corporate securities, municipal securities and government securities. Investments classified as available-for-sale are stated at fair value with unrealized gains and losses, net of taxes, reported in Accumulated other comprehensive income. The Company classifies its available-for-sale investments as current and non-current based on their actual remaining time to maturity. The Company does not recognize changes in the fair value of its available-for-sale investments in income unless a decline in value is considered other-than-temporary in accordance with the authoritative guidance. The Company’s investment policy is designed to limit exposure to any one issuer depending on credit quality. The Company uses information provided by third parties to adjust the carrying value of certain of its investments to fair value at the end of each period. Fair values are based on a variety of inputs and may include interest rates, known historical trades, yield curve information, benchmark data, prepayment speeds, credit quality and broker/dealer quotes.
Inventory	Inventory Inventories are stated at the lower of cost or market on a standard cost basis, which approximates actual cost. The Company’s inventories as of March 31, 2014 and December 31, 2013 primarily consist of finished goods.
Revenue Recognition	Revenue Recognition Net revenues include the following categories: Product and licenses, SaaS, License updates and maintenance and Professional services. Product and licenses revenues primarily represent fees related to the licensing of the Company’s software and hardware appliance products. These revenues are reflected net of sales allowances, cooperative advertising agreements, partner incentive programs and provisions for returns. Shipping charges billed to customers are included in Product and license revenue and the related shipping costs are included in Cost of product and license revenue. SaaS revenues consist primarily of fees related to online service agreements, which are recognized ratably over the contract term, which is typically 12 months. In addition, SaaS revenues may also include set-up fees, which are recognized ratably over the contract term or the expected customer life, whichever is longer. License updates and maintenance revenues consist of fees related to the Subscription Advantage program and maintenance fees, which include technical support and hardware and software maintenance. The Company licenses many of its virtualization products bundled with a one-year contract for its Subscription Advantage program. Subscription Advantage is a renewable program that provides subscribers with immediate access to software upgrades, enhancements and maintenance releases when and if they become available during the term of the contract. Subscription Advantage and maintenance fees are recognized ratably over the term of the contract, which is typically 12 to 24 months. The Company capitalizes certain third-party commissions related to Subscription Advantage renewals. The capitalized commissions are amortized to Sales, marketing and services expense at the time the related deferred revenue is recognized as revenue. Hardware and software maintenance and support contracts are typically sold separately. Hardware maintenance includes technical support, the latest software upgrades and replacement of malfunctioning appliances. Dedicated account management is available as an add-on to the program for a higher level of service. Software maintenance includes unlimited support with product version upgrades. Professional services revenues are comprised of fees from consulting services related to the implementation of the Company’s products and fees from product training and certification, which are recognized as the services are provided. The Company recognizes revenue when it is earned and when all of the following criteria are met: persuasive evidence of the arrangement exists; delivery has occurred or the service has been provided and the Company has no remaining obligations; the fee is fixed or determinable; and collectability is probable. The majority of the Company’s product and license revenue consists of revenue from the sale of stand-alone software products. Stand-alone software sales generally include a perpetual license to the Company’s software and is subject to the industry specific software revenue recognition guidance. In accordance with this guidance, the Company allocates revenue to license updates related to its stand-alone software and any other undelivered elements of the arrangement based on vendor specific objective evidence (“VSOE”) of fair value of each element and such amounts are deferred until the applicable delivery criteria and other revenue recognition criteria described above have been met. The balance of the revenues, net of any discounts inherent in the arrangement, is recognized at the outset of the arrangement using the residual method as the product licenses are delivered. If management cannot objectively determine the fair value of each undelivered element based on VSOE of fair value, revenue recognition is deferred until all elements are delivered, all services have been performed, or until fair value can be objectively determined. For hardware appliance transactions, the arrangement consideration is allocated to stand-alone software deliverables as a group and the non-software deliverables based on the relative selling prices using the selling price hierarchy in the amended revenue recognition guidance. The selling price hierarchy for a deliverable is based on its VSOE if available, third-party evidence of selling price ("TPE") if VSOE is not available, or estimated selling price ("ESP") if neither VSOE nor TPE is available. The Company then recognizes revenue on each deliverable in accordance with its policies for product and service revenue recognition. VSOE of selling price is based on the price charged when the element is sold separately. In determining VSOE, the Company requires that a substantial majority of the selling prices fall within a reasonable range based on historical discounting trends for specific products and services. TPE of selling price is established by evaluating competitor products or services in stand-alone sales to similarly situated customers. However, as the Company’s products contain a significant element of proprietary technology and its solutions offer substantially different features and functionality, the comparable pricing of products with similar functionality typically cannot be obtained. Additionally, as the Company is unable to reliably determine what competitors products’ selling prices are on a stand-alone basis, the Company is not typically able to determine TPE. The estimate of selling price is established considering multiple factors including, but not limited to, pricing practices in different geographies and through different sales channels and competitor pricing strategies. For the Company’s non-software deliverables, it allocates the arrangement consideration based on the relative selling price of the deliverables. For the Company’s hardware appliances, it uses ESP as its selling price. For the Company’s support and services, it generally uses VSOE as its selling price. When the Company is unable to establish selling price using VSOE for its support and services, the Company uses ESP in its allocation of arrangement consideration. The Company’s SaaS products are considered service arrangements per the authoritative guidance; accordingly, the Company follows the provisions of Securities and Exchange Commission Staff Accounting Bulletin (“SAB”) No. 104, Revenue Recognition, when accounting for these service arrangements. Generally, the Company’s SaaS products are sold separately and not bundled with the Company's Enterprise and Service Provider products and services. In the normal course of business, the Company is not obligated to accept product returns from its distributors under any conditions, unless the product item is defective in manufacture. The Company establishes provisions for estimated returns, as well as other sales allowances, concurrently with the recognition of revenue. The provisions are established based upon consideration of a variety of factors, including, among other things, recent and historical return rates for both specific products and distributors and the impact of any new product releases and projected economic conditions. Product returns are provided for in the condensed consolidated financial statements and have historically been within management’s expectations. Allowances for estimated product returns amounted to approximately $1.3 million and $2.1 million at March 31, 2014 and December 31, 2013, respectively. The Company also records estimated reductions to revenue for customer programs and incentive offerings, including volume-based incentives. The Company could take actions to increase its customer incentive offerings, which could result in an incremental reduction to revenue at the time the incentive is offered.
Foreign Currency	Foreign Currency The functional currency for all of the Company’s wholly-owned foreign subsidiaries in its Enterprise and Service Provider segment is the U.S. dollar. Monetary assets and liabilities of such subsidiaries are remeasured into U.S. dollars at exchange rates in effect at the balance sheet date, and revenues and expenses are remeasured at average rates prevailing during the year. The functional currency of the Company’s wholly-owned foreign subsidiaries of its SaaS segment is the currency of the country in which each subsidiary is located. The Company translates assets and liabilities of these foreign subsidiaries at exchange rates in effect at the balance sheet date. The Company includes accumulated net translation adjustments in equity as a component of Accumulated other comprehensive income. Foreign currency transaction gains and losses are the result of exchange rate changes on transactions denominated in currencies other than the functional currency, including U.S. dollars. The remeasurement of those foreign currency transactions is included in determining net income or loss for the period of exchange. See Note 9 for information on the Company's Enterprise and Service Provider and SaaS segments.
Accounting for Stock-Based Compensation Plans	Accounting for Stock-Based Compensation Plans The Company has various stock-based compensation plans for its employees and outside directors and accounts for stock-based compensation arrangements in accordance with the authoritative guidance, which requires the Company to measure and record compensation expense in its condensed consolidated financial statements using a fair value method. See Note 7 for further information regarding the Company’s stock-based compensation plans.

Disclosure of accounting policy for (1) transactions denominated in a currency other than the reporting enterprise's functional currency, (2) translating foreign currency financial statements that are incorporated into the financial statements of the reporting enterprise by consolidation, combination, or the equity method of accounting, and (3) remeasurement of the financial statements of a foreign reporting enterprise in a hyperinflationary economy.

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Disclosure of accounting policy for major classes of inventories, bases of stating inventories (for example, lower of cost or market), methods by which amounts are added and removed from inventory classes (for example, FIFO, LIFO, or average cost), loss recognition on impairment of inventories, and situations in which inventories are stated above cost. If inventory is carried at cost, this disclosure includes the nature of the cost elements included in inventory.

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Disclosure of accounting policy for investments in financial assets, including marketable securities (debt and equity securities with readily determinable fair values), investments accounted for under the equity method and cost method, securities borrowed and loaned, and repurchase and resale agreements. For marketable securities, the disclosure may include the entity's accounting treatment for transfers between investment categories and how the fair values for such securities are determined. Also, for all investments, an entity may describe its policy for assessing, recognizing and measuring impairment of the investment.

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Disclosure of accounting policy for revenue recognition. If the entity has different policies for different types of revenue transactions, the policy for each material type of transaction is generally disclosed. If a sales transaction has multiple element arrangements (for example, delivery of multiple products, services or the rights to use assets) the disclosure may indicate the accounting policy for each unit of accounting as well as how units of accounting are determined and valued. The disclosure may encompass important judgment as to appropriateness of principles related to recognition of revenue. The disclosure also may indicate the entity's treatment of any unearned or deferred revenue that arises from the transaction.

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