Fair Value Measurements (Fair Value of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Weighted Average Discount Rate 17.00% 18.00%
Maximum potential payout of acquisition-related contingent consideration   $ 10
Fair Value    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total assets at fair value 1,211 1,229
Total liabilities at fair value 18 19
Quoted Prices In Active Markets For Identical Financial Instruments (Level 1)    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total assets at fair value 405 715
Total liabilities at fair value 9 9
Significant Other Observable Inputs (Level 2) [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total assets at fair value 806 514
Total liabilities at fair value 9 6
Fair Value, Inputs, Level 3 [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Total liabilities at fair value 0 4
Cash Equivalents [Member] | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Bank Time Deposits [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value, Cash equivalents 175  
Cash Equivalents [Member] | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Money Market Funds [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value, Cash equivalents 7 588
Short-Term Investments [Member] | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | U.S. Treasury Securities [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value, Available-for-sale of securities 214  
Short-Term Investments [Member] | Significant Other Observable Inputs (Level 2) [Member] | Corporate Bonds [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value, Available-for-sale of securities   279
Short-Term Investments And Cash Equivalents | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | U.S. Treasury Securities [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value, Available-for-sale of securities   118
Short-Term Investments And Cash Equivalents | Significant Other Observable Inputs (Level 2) [Member] | Corporate Bonds [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value, Available-for-sale of securities 468  
Short-Term Investments And Cash Equivalents | Significant Other Observable Inputs (Level 2) [Member] | US Agencies Securities [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value, Available-for-sale of securities 180 89
Short-Term Investments And Cash Equivalents | Significant Other Observable Inputs (Level 2) [Member] | Commercial Paper [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value, Available-for-sale of securities 140 146
Other Current Assets [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Currency Derivatives [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value, Foreign currency derivatives, assets 18  
Other Assets [Member] | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Deferred compensation plan assets    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value, Deferred compensation plan assets and liabilities 9 [1] 9 [1]
Accrued and Other Current Liabilities | Significant Other Observable Inputs (Level 2) [Member] | Foreign Currency Derivatives [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value, Foreign currency derivatives, liabilities 9 6
Other Liabilities [Members] | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Deferred Compensation Plan Liabilities [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value, Deferred compensation plan assets and liabilities 9 [1] 9 [1]
Accrued And Other Current Liabilities And Other Liabilities | Fair Value, Inputs, Level 3 [Member] | Contingent Consideration [Member]    
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]    
Fair value, Contingent consideration $ 0 [2] $ 4 [2]
[1] The Deferred Compensation Plan assets consist of various mutual funds. See Note 15 for additional information regarding our Deferred Compensation Plan.
[2] The contingent consideration as of March 31, 2014 represented the estimated fair value of the additional variable cash consideration payable in connection with our acquisitions of KlickNation Corporation (“KlickNation”) and Chillingo Limited (“Chillingo”) that were contingent upon the achievement of certain performance milestones. We estimated the fair value of the acquisition-related contingent consideration payable using probability-weighted discounted cash flow models, and applied a discount rate that appropriately captured the risk associated with the obligation. The weighted average of the discount rates used during the fiscal year 2015 was 17 percent. The weighted average of the discount rates used during the fiscal year 2014 was 18 percent. The significant unobservable input used in the fair value measurement of the contingent consideration payable was forecasted earnings. At March 31, 2014, the fair market value of acquisition-related contingent consideration totaled $4 million, compared to a maximum potential payout of $10 million. At March 31, 2015, the KlickNation earn-out expired.