| **Net Income Per Share (Tables)**                                    | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|----------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
||
| **Earnings Per Share Reconciliation [Abstract]**                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] | The following table summarizes the computations of basic earnings per share (“Basic EPS”) and diluted earnings per share (“Diluted EPS”). Basic EPS is computed as net income divided by the weighted-average number of common shares outstanding for the period. Diluted EPS reflects the potential dilution that could occur from common shares issuable through stock-based compensation plans including stock options, restricted stock, restricted stock units, common stock through our ESPP, warrants, and other convertible securities using the treasury stock method. Three Months Ended June 30,(In millions, except per share amounts)2013 2012Net income$222 $201Shares used to compute net income per share:   Weighted-average common stock outstanding - basic304 317Dilutive potential common shares8 3Weighted-average common stock outstanding - diluted312 320Net income per share:   Basic$0.73 $0.63Diluted$0.71 $0.63 |

| X                                                                                                                                                                          |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_EarningsPerShareReconciliationAbstract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Tabular disclosure of an entity's basic and diluted earnings per share calculations.
+ References
No definition available.
+ Details**Name:**us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock**Namespace Prefix:**us-gaap_**Data Type:**nonnum:textBlockItemType**Balance Type:**na**Period Type:**duration |