Stock-Based Compensation (Schedule Of Stock-Based Compensation Expense By Statement Of Operations) (Details) - USD ($)
$ in Millions |
3 Months Ended |
6 Months Ended |
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] |
|
|
|
|
| Excess Tax Benefit from Share-based Compensation, Financing Activities |
$ 4
|
$ 25
|
$ 37
|
$ 65
|
| Stock-based compensation expense |
48
|
44
|
96
|
89
|
| Cost of Sales [Member] |
|
|
|
|
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] |
|
|
|
|
| Stock-based compensation expense |
1
|
1
|
2
|
1
|
| Research And Development [Member] |
|
|
|
|
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] |
|
|
|
|
| Stock-based compensation expense |
27
|
25
|
54
|
51
|
| Marketing and Sales [Member] |
|
|
|
|
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] |
|
|
|
|
| Stock-based compensation expense |
8
|
7
|
15
|
12
|
| General And Administrative [Member] |
|
|
|
|
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] |
|
|
|
|
| Stock-based compensation expense |
12
|
$ 11
|
25
|
$ 25
|
| Stock-based compensation expense [Member] |
|
|
|
|
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] |
|
|
|
|
| Deferred Income Tax Expense (Benefit) |
$ 9
|
|
$ 18
|
|