| **Stock-Based Compensation And Employee Benefit Plans** | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         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| **Share-based Compensation [Abstract]**                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                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| Stock-Based Compensation And Employee Benefit Plans     | (15)  STOCK-BASED COMPENSATION AND EMPLOYEE BENEFIT PLANSValuation AssumptionsWe estimate the fair value of share-based payment awards on the date of grant. We recognize compensation costs for stock-based payment awards to employees based on the grant-date fair value using a straight-line approach over the service period for which such awards are expected to vest. For awards with only service conditions that has a graded vesting schedule, we recognize compensation costs on a straight-line basis over the requisite service period for the entire award.We determine the fair value of our share-based payment awards as follows:•Restricted Stock Units, Restricted Stock, and Performance-Based Restricted Stock Units. The fair value of restricted stock units, restricted stock, and performance-based restricted stock units (other than market-based restricted stock units) is determined based on the quoted market price of our common stock on the date of grant. Performance-based restricted stock units include grants made (1) to certain members of executive management primarily granted in fiscal year 2009 and (2) in connection with certain acquisitions.•Market-Based Restricted Stock Units. Market-based restricted stock units consist of grants of performance-based restricted stock units to certain members of executive management that vest contingent upon the achievement of pre-determined market and service conditions (referred to herein as “market-based restricted stock units”). The fair value of our market-based restricted stock units is determined using a Monte-Carlo simulation model. Key assumptions for the Monte-Carlo simulation model are the risk-free interest rate, expected volatility, expected dividends and correlation coefficient.•Stock Options and Employee Stock Purchase Plan. The fair value of stock options and stock purchase rights granted pursuant to our equity incentive plans and our 2000 Employee Stock Purchase Plan (“ESPP”), respectively, is determined using the Black-Scholes valuation model based on the multiple-award valuation method. Key assumptions of the Black-Scholes valuation model are the risk-free interest rate, expected volatility, expected term and expected dividends.The determination of the fair value of market-based restricted stock units, stock options and ESPP is affected by assumptions regarding subjective and complex variables. Generally, our assumptions are based on historical information and judgment is required to determine if historical trends may be indicators of future outcomes.The estimated assumptions used in the Black-Scholes valuation model to value our stock option grants and ESPP were as follows:  Stock Option Grants ESPP  Year Ended March 31, Year Ended March 31,  2014 2013 2012 2014 2013 2012Risk-free interest rate 1.6% 0.4 - 1.0% 0.4 - 1.8% 0.1% 0.1 - 0.2% 0.1 - 0.2%Expected volatility 37 - 42% 40 - 46% 40 - 46% 36 - 38% 35 - 42% 39 - 41%Weighted-average volatility 37% 43% 43% 38% 38% 41%Expected term 4.5 years 4.4 years 4.4 years 6 - 12 months 6 - 12 months 6 - 12 monthsExpected dividends None None None None None NoneThe estimated assumptions used in the Monte-Carlo simulation model to value our market-based restricted stock units were as follows:  Year  Ended March 31, 2014 Year  Ended March 31, 2013 Year  Ended March 31, 2012Risk-free interest rate0.4% 0.2 - 0.4% 0.2 -0.6%Expected volatility16 - 58% 17 - 116% 14 - 83%Weighted-average volatility31% 35% 35%Expected dividendsNone None NoneStock-Based Compensation ExpenseEmployee stock-based compensation expense recognized during the fiscal years ended March 31, 2014, 2013 and 2012 was calculated based on awards ultimately expected to vest and has been reduced for estimated forfeitures. In subsequent periods, if actual forfeitures differ from those estimates, an adjustment to stock-based compensation expense will be recognized at that time.The following table summarizes stock-based compensation expense resulting from stock options, restricted stock, restricted stock units, performance-based restricted stock units, market-based restricted stock units, and the ESPP included in our Consolidated Statements of Operations (in millions):  Year Ended March 31,  2014 2013 2012Cost of revenue $2 $2 $2Research and development 90 94 103Marketing and sales 26 30 27General and administrative 32 38 38Stock-based compensation expense $150 $164 $170During the fiscal years ended March 31, 2014, 2013 and 2012, we did not recognize any benefit from income taxes related to our stock-based compensation expense.As of March 31, 2014, our total unrecognized compensation cost related to stock options was $9 million and is expected to be recognized over a weighted-average service period of 3.6 years. As of March 31, 2014, our total unrecognized compensation cost related to restricted stock and restricted stock units (collectively referred to as “restricted stock rights”) was $220 million and is expected to be recognized over a weighted-average service period of 1.6 years. Of the $220 million of unrecognized compensation cost, $14 million relates to market-based restricted stock units.For fiscal year ended March 31, 2014, we recognized $13 million of tax benefit from the exercise of stock options; this amount is reported in the financing activities on our Consolidated Statements of Cash Flows. For the fiscal year ended March 31, 2013, we recognized $1 million of tax expense from the exercise of stock options, net of $1 million of deferred tax write-offs. There was no tax benefit related to stock-based compensation reported in the financing activities on our Consolidated Statements of Cash Flows. For the fiscal year ended March 31, 2012, we recognized $3 million of tax benefit from the exercise of stock options, net of $1 million of deferred tax write-offs; of this amount $4 million of excess tax benefit related to stock-based compensation was reported in the financing activities on our Consolidated Statements of Cash Flows.Summary of Plans and Plan ActivityEquity Incentive PlansOur 2000 Equity Incentive Plan (the “Equity Plan”) allows us to grant options to purchase our common stock and to grant restricted stock, restricted stock units and stock appreciation rights to our employees, officers and directors. Pursuant to the Equity Plan, incentive stock options may be granted to employees and officers and non-qualified options may be granted to employees, officers and directors, at not less than 100 percent of the fair market value on the date of grant.Options granted under the Equity Plan generally expire ten years from the date of grant and are generally exercisable as to 24 percent of the shares after 12 months, and then ratably over the following 38 months.  At our Annual Meeting of Stockholders, held on July 31, 2013, our stockholders approved (a) amendments to our 2000 Equity Incentive Plan (the “Equity Plan”) to increase the number of shares of common stock authorized under the Equity Plan by 18 million shares, and to increase the limit on the number of shares that may be covered by equity awards to new employees under the Equity Plan from a maximum of 2 million shares in the fiscal year of hire to 4 million shares in the fiscal year of hire, and (b) an amendment to the ESPP to increase the number of shares authorized under the ESPP by 7 million shares. A total of 24.2 million options or 17.0 million restricted stock units were available for grant under our Equity Plan as of March 31, 2014.  Stock OptionsThe following table summarizes our stock option activity for the fiscal year ended March 31, 2014:   Options(in thousands) Weighted-AverageExercise Prices Weighted-AverageRemainingContractualTerm   (in years) AggregateIntrinsic Value(in millions)Outstanding as of March 31, 2013 7,802 $34.17    Granted 1,013 26.21    Exercised (2,445) 18.09    Forfeited, cancelled or expired (1,059) 47.31    Outstanding as of March 31, 2014 5,311 $37.43 4.59 $18Vested and expected to vest 5,096 $37.92 4.38 $17Exercisable as of March 31, 2014 4,191 $40.70 3.31 $14As of March 31, 2014, the weighted-average remaining contractual term for our stock options outstanding was 4.59 years and the aggregate intrinsic value of our stock options outstanding was $18 million. The aggregate intrinsic value represents the total pre-tax intrinsic value based on our closing stock price as of March 31, 2014, which would have been received by the option holders had all the option holders exercised their options as of that date. The weighted-average grant date fair values of stock options granted during fiscal years 2014, 2013, and 2012 were $8.61, $4.64 and $7.27, respectively. The total intrinsic values of stock options exercised during fiscal years 2014 and 2012 were $16 million and $4 million, respectively, and immaterial for fiscal year 2013. The total estimated fair values (determined as of the grant date) of stock options vested during fiscal years 2014, 2013 and 2012 were $2 million, $11 million and $15 million, respectively. We issue new common stock from our authorized shares upon the exercise of stock options.The following table summarizes outstanding and exercisable stock options as of March 31, 2014:   Options Outstanding Options ExercisableRange ofExercise Prices Numberof Shares(in thousands) Weighted-AverageRemainingContractualTerm  (in years) Weighted-AverageExercisePrices PotentialDilution Numberof Shares(in thousands) Weighted-AverageExercisePrices PotentialDilution$11.53 - $19.99 911 4.90 $17.40 0.3% 845 $17.69 0.3%20.00 - 29.99 1,752 7.76 24.03 0.6% 697 21.16 0.2%30.00 - 39.99  8 4.50 36.00 —% 8 36.00 —%40.00 - 59.99 2,271 2.63 51.34 0.7% 2,272 51.34 0.7%60.00 - 64.92 369 0.83 64.85 0.1% 369 64.85 0.1%$11.53 - $64.92 5,311 4.59 $37.43 1.7% 4,191 $40.70 1.3%Potential dilution is computed by dividing the options in the related range of exercise prices by 311 million shares of common stock, which were issued and outstanding as of March 31, 2014.Restricted Stock RightsWe grant restricted stock rights under our Equity Plan to employees worldwide. Restricted stock units entitle holders to receive shares of common stock at the end of a specified period of time. Upon vesting, the equivalent number of common shares is typically issued net of required tax withholdings, if any. Restricted stock is issued and outstanding upon grant; however, restricted stock award holders are restricted from selling the shares until they vest. Upon granting or vesting of restricted stock, as the case may be, we will typically withhold shares to satisfy tax withholding requirements. Restricted stock rights are subject to forfeiture and transfer restrictions. Vesting for restricted stock rights is based on the holders’ continued employment with us. If the vesting conditions are not met, unvested restricted stock rights will be forfeited. Generally, our restricted stock rights vest according to one of the following vesting schedules:•Three-year vesting with  1/3 cliff vesting at the end of each year;•Three-year vesting with 100% cliff vesting at the end of year three;•Four-year vesting with  1/4 cliff vesting at the end of each year;•Five-year vesting with  1/9,  2/9,  3/9,  2/9 and  1/9 of the shares cliff vesting respectively at the end of each of the 1st, 2nd, 3rd, 4th, and 5th years;•Three-year vesting with  1/2 cliff vesting after 18 and 36 months;•35 month vesting with  1/3 cliff vesting after 11, 23 and 35 months or;•One-year vesting with 100% cliff vesting at the end of one year.Each restricted stock right granted reduces the number of shares available for grant by 1.43 shares under our Equity Plan. The following table summarizes our restricted stock rights activity, excluding performance-based restricted stock unit activity which is discussed below, for the fiscal year ended March 31, 2014:   RestrictedStock Rights(in thousands) Weighted-Average GrantDate Fair ValuesBalance as of March 31, 2013 15,918 $16.85Granted 7,364 23.01Vested (6,893) 17.37Forfeited or cancelled (2,853) 17.99Balance as of March 31, 2014 13,536 $19.70The grant date fair value of restricted stock rights is based on the quoted market price of our common stock on the date of grant. The weighted-average grant date fair values of restricted stock rights granted during fiscal years 2014, 2013, and 2012 were $23.01, $12.85 and $21.38, respectively. The total grant date fair values of restricted stock rights that vested during fiscal years 2014, 2013, and 2012 were $120 million, $143 million and $165 million, respectively.Performance-Based Restricted Stock UnitsOur performance-based restricted stock units vest contingent upon the achievement of pre-determined performance-based milestones. If these performance-based milestones are not met, the restricted stock units will not vest, in which case, any compensation expense we have recognized to date will be reversed.The following table summarizes our performance-based restricted stock unit activity for the fiscal year ended March 31, 2014:   Performance-Based RestrictedStock Units(in thousands) Weighted-Average GrantDate Fair ValuesBalance as of March 31, 2013 1,324 $51.54Vested  (36) 15.39Forfeited or cancelled (1,234) 48.32Balance as of March 31, 2014 54 $15.39The grant date fair value of performance-based restricted stock units is based on the quoted market price of our common stock on the date of grant. There were no performance-based restricted stock units granted during fiscal years 2014, 2013, and 2012. The total grant date fair values of performance-based restricted stock units that vested during fiscal years 2014 and 2013 was less than $1 million. No performance-based restricted stock units vested during fiscal year 2012.Market-Based Restricted Stock UnitsOur market-based restricted stock units vest contingent upon the achievement of pre-determined market and service conditions. If these market conditions are not met but service conditions are met, the restricted stock units will not vest; however, any compensation expense we have recognized to date will not be reversed. The number of shares of common stock to be received at vesting will range from zero percent to 200 percent of the target number of stock units based on our total stockholder return (“TSR”) relative to the performance of companies in the NASDAQ-100 Index for each measurement period, generally over a three year period. We present shares granted at 100 percent of target of the number of stock units that may potentially vest. The maximum number of common shares that could vest is approximately 1.1 million for market-based restricted stock units granted in the fiscal year 2014. As of March 31, 2014, the maximum number of shares that could vest is approximately 2.0 million for market-based restricted stock units outstanding. The following table summarizes our market-based restricted stock unit activity for the year ended March 31, 2014:   Market-BasedRestricted  StockUnits(in thousands) Weighted-Average  GrantDate Fair ValueBalance as of March 31, 2013 925 $19.16Granted 555 29.52Vested (304) 16.01Vested above target 24 10.45Forfeited or cancelled (222) 23.47Balance as of March 31, 2014 978 $24.83The weighted-average grant date fair values of market-based restricted stock units granted during fiscal years 2014, 2013, and 2012 were $29.52, $12.41, and $33.70 respectively. The total grant date fair value of market-based restricted stock units that vested during fiscal years 2014 and 2013 were $4.9 million and $3.7 million, respectively. No market-based restricted stock units vested during fiscal year 2012.ESPPPursuant to our ESPP, eligible employees may authorize payroll deductions of between 2 percent and 10 percent of their compensation to purchase shares at 85 percent of the lower of the market price of our common stock on the date of commencement of the offering or on the last day of each six-month purchase period.During fiscal year 2014, we issued approximately 2 million shares under the ESPP with exercise prices for purchase rights ranging from $11.33 to $22.64. During fiscal years 2014, 2013, and 2012, the estimated weighted-average fair values of purchase rights were $4.67, $4.83 and $4.98, respectively.We issue new common stock out of the ESPP’s pool of authorized shares. The fair values above were estimated on the date of grant using the Black-Scholes option-pricing model assumptions.Deferred Compensation PlanWe have a Deferred Compensation Plan (“DCP”) for the benefit of a select group of management or highly compensated employees and Directors, which is unfunded and intended to be a plan that is not qualified within the meaning section 401(a) of the Internal Revenue Code. The DCP permits the deferral of the annual base salary and/or Director fees up to a maximum amount. The deferrals are held in a separate trust, which has been established by us to administer the DCP. The trust is a grantor trust and the specific terms of the trust agreement provide that the assets of the trust are available to satisfy the claims of general creditors in the event of our insolvency. The assets held by the trust are classified as trading securities and are held at fair value on our Consolidated Balance Sheets. The assets and liabilities of the DCP are presented in other assets and other liabilities on our Consolidated Balance Sheets, respectively, with changes in the fair value of the assets and in the deferred compensation liability recognized as compensation expense. The estimated fair value of the assets was $9 million and $11 million as of March 31, 2014 and 2013, respectively. As of March 31, 2014 and 2013, $9 million and $12 million were recorded respectively to recognize undistributed deferred compensation due to employees.401(k) Plan and Registered Retirement Savings PlanWe have a 401(k) plan covering substantially all of our U.S. employees, and a Registered Retirement Savings Plan covering substantially all of our Canadian employees. These plans permit us to make discretionary contributions to employees’ accounts based on our financial performance. We contributed an aggregate of $9 million, $14 million and $13 million to these plans in fiscal years 2014, 2013, and 2012, respectively. Stock Repurchase ProgramIn February 2011, our Board of Directors authorized a program to repurchase up to $600 million of our common stock over the following 18 months. We completed that program in April 2012. We repurchased approximately 32 million shares in the open market under this program, including pursuant to pre-arranged stock trading plans. In July 2012, our Board of Directors authorized a program to repurchase up to $500 million of our common stock. We repurchased approximately 22 million shares in the open market under this program, including pursuant to pre-arranged stock trading plans.The following table summarizes total shares repurchased and retired during fiscal years 2013 and 2012:  February 2011 Program July 2012 Program Total(In millions)Shares Amount Shares Amount Shares AmountFiscal Year 201225 $471 — $— 25 $471Fiscal Year 20134 $71 22 $278 26 $349During fiscal year 2014, we did not repurchase any shares of our common stock.In May 2014, a special committee of our Board of Directors, on behalf of the full Board of Directors, authorized a new program to repurchase up to $750 million of our common stock.  This new stock repurchase program, which expires on May 31, 2016, supersedes and replaces the stock repurchase authorization approved by our Board of Directors in July 2012.  Under this program, we may purchase stock in the open market or through privately-negotiated transactions in accordance with applicable securities laws, including pursuant to pre-arranged stock trading plans. The timing and actual amount of the stock repurchases will depend on several factors including price, capital availability, regulatory requirements, alternative investment opportunities and other market conditions. We are not obligated to repurchase any specific number of shares under this program and it may be modified, suspended or discontinued at any time. |

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| - Definition
The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.
+ References
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