| **Balance Sheet Details (Tables)**               | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                             |
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| **Balance Sheet Related Disclosures [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| Inventories Schedule                             | Inventories as of March 31, 2016 and 2015 consisted of (in millions):  As of March 31, 2016 2015Finished goods$32 $35Raw materials and work in process1 1Inventories$33 $36                                                                                                                                                                                                                                              |
| Property And Equipment, Net Schedule             | Property and equipment, net, as of March 31, 2016 and 2015 consisted of (in millions):  As of March 31, 2016 2015Computer equipment and software$684 $655Buildings313 315Leasehold improvements129 126Equipment, furniture and fixtures, and other80 73Land61 62Construction in progress15 7 1,282 1,238Less: accumulated depreciation(843) (779)Property and equipment, net$439 $459 |
| Accrued And Other Current Liabilities Schedule   | Accrued and other current liabilities as of March 31, 2016 and 2015 consisted of (in millions):  As of March 31, 2016 2015Other accrued expenses$218 $298Accrued compensation and benefits256 263Accrued royalties159 119Deferred net revenue (other)77 114Accrued and other current liabilities$710 $794                                                                                                      |

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| - Definition
The entire disclosure for accounts payable and accrued liabilities at the end of the reporting period.
+ References
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| - Definition
The entire disclosure for long-lived, physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, accounting policies and methodology, roll forwards, depreciation, depletion and amortization expense, including composite depreciation, accumulated depreciation, depletion and amortization expense, useful lives and method used, income statement disclosures, assets held for sale and public utility disclosures.
+ References
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| - Definition
Tabular disclosure of the carrying amount as of the balance sheet date of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.
+ References
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