| **Interest And Other Income (Expense), Net (Tables)** | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
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| **Interest and Other Income [Abstract]**              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| Schedule Of Interest And Other Income (Expense), Net  | Interest and other income (expense), net, for the fiscal years ended March 31, 2016, 2015 and 2014 consisted of (in millions):  Year Ended March 31, 2016 2015 2014Loss on conversion of Convertible Notes$(10) $— $—Interest expense(28) (31) (30)Interest income15 10 5Net gain (loss) on foreign currency transactions(14) (62) 4Net gain (loss) on foreign currency forward contracts15 59 (5)Other income, net1 1 —Interest and other income (expense), net$(21) $(23) $(26) |

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| - References
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| - Definition
Tabular disclosure of the components of non-operating income or non-operating expense that may include amounts earned from dividends, interest on securities, gains (losses) on securities sold, equity earnings of unconsolidated affiliates, net gain (loss) on sales of business, interest expense and other miscellaneous income or expense items.
+ References
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