(Fair Value Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($)
$ in Millions |
Sep. 30, 2016 |
Mar. 31, 2016 |
| Fair Value |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Total assets at fair value |
|
$ 2,023
|
$ 1,915
|
| Total liabilities at fair value |
|
21
|
19
|
| Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Total assets at fair value |
|
809
|
903
|
| Total liabilities at fair value |
|
10
|
9
|
| Significant Other Observable Inputs (Level 2) |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Total assets at fair value |
|
1,214
|
1,012
|
| Total liabilities at fair value |
|
11
|
10
|
| Fair Value, Inputs, Level 3 [Member] |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Total assets at fair value |
|
0
|
0
|
| Total liabilities at fair value |
|
0
|
0
|
| Short-term investments | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | U.S. Treasury securities |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Fair value, Available-for-sale of securities |
|
379
|
|
| Short-term investments | Significant Other Observable Inputs (Level 2) | Corporate bonds |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Fair value, Available-for-sale of securities |
|
739
|
|
| Short-term investments | Significant Other Observable Inputs (Level 2) | Foreign Government Debt Securities [Member] |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Fair value, Available-for-sale of securities |
|
115
|
|
| Short-term investments | Significant Other Observable Inputs (Level 2) | Asset-backed Securities [Member] |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Asset-backed securities |
|
54
|
|
| Short-Term Investments And Cash Equivalents | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | U.S. Treasury securities |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Fair value, Available-for-sale of securities |
|
|
407
|
| Short-Term Investments And Cash Equivalents | Significant Other Observable Inputs (Level 2) | Corporate bonds |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Fair value, Available-for-sale of securities |
|
|
623
|
| Short-Term Investments And Cash Equivalents | Significant Other Observable Inputs (Level 2) | U.S. agency securities |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Fair value, Available-for-sale of securities |
|
163
|
170
|
| Short-Term Investments And Cash Equivalents | Significant Other Observable Inputs (Level 2) | Commercial paper |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Fair value, Available-for-sale of securities |
|
110
|
81
|
| Short-Term Investments And Cash Equivalents | Significant Other Observable Inputs (Level 2) | Foreign Government Debt Securities [Member] |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Fair value, Available-for-sale of securities |
|
|
122
|
| Cash Equivalents | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Bank Time Deposits [Member] |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Fair value, Cash equivalents |
|
236
|
345
|
| Cash Equivalents | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Money market funds |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Fair value, Cash equivalents |
|
185
|
143
|
| Other Current Assets and Other Assets [Domain] | Significant Other Observable Inputs (Level 2) | Foreign currency derivatives |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Fair value, Foreign currency derivatives, assets |
|
33
|
16
|
| Other assets | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Deferred compensation plan assets |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Fair value, Deferred compensation plan assets |
[1] |
9
|
8
|
| Accrued and Other Current Liabilities and Other Liabilities | Significant Other Observable Inputs (Level 2) | Foreign currency derivatives |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Fair value, Foreign currency derivatives, liabilities |
|
11
|
10
|
| Other liabilities | Quoted Prices In Active Markets For Identical Financial Instruments (Level 1) | Deferred Compensation Plan Liabilities |
|
|
|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions |
|
|
|
| Fair value, Deferred compensation plan assets |
[1] |
$ 10
|
$ 9
|
|
|