| **Earnings (Loss) Per Share**                    | 9 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
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| **Earnings Per Share Reconciliation [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| Earnings (Loss) Per Share                        | (13) EARNINGS (LOSS) PER SHAREThe 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 December 31,  Nine Months Ended December 31,(In millions, except per share amounts)2015 2014 2015 2014Net income (loss)$(45) $142 $257 $480Shares used to compute earnings (loss) per share:       Weighted-average common stock outstanding — basic311 311 311 312Dilutive potential common shares related to stock award plans and from assumed exercise of stock options— 8 7 8Dilutive potential common shares related to the Notes— 4 8 2Dilutive potential common shares related to the Warrants— — 7 —Weighted-average common stock outstanding — diluted311 323 333 322Earnings (loss) per share:       Basic$(0.14) $0.46 $0.83 $1.54Diluted$(0.14) $0.44 $0.77 $1.49As a result of our net loss for the three months ended December 31, 2015, we have excluded all potentially dilutive common shares from the diluted loss per share calculation as their inclusion would have had an antidilutive effect. Had we reported net income for this period, an additional 6 million shares of common stock related to our outstanding equity-based instruments, an additional 6 million shares of common stock related to the Notes, and an additional 8 million shares related to the Warrants would have been included in the number of shares used to calculate Diluted EPS for the three months ended December 31, 2015. For the nine months ended December 31, 2015, an immaterial amount of options to purchase, restricted stock units and restricted stock to be released were excluded from the treasury stock method computation of diluted shares as their inclusion would have had an antidilutive effect.For the three and nine months ended December 31, 2014, options to purchase, restricted stock units and restricted stock to be released in the amount of 4 million shares were excluded from the treasury stock method computation of diluted shares as their inclusion would have had an antidilutive effect.For the three and nine months ended December 31, 2014, potentially dilutive shares of common stock related to Warrants, which have a conversion price of $41.14 per share, were excluded from the computation of Diluted EPS as their inclusion would have had an antidilutive effect resulting from the conversion price. The associated Convertible Note Hedge was excluded from the computation of diluted shares as the impact is always considered antidilutive. See Note 10 for additional information related to our 0.75% Convertible Senior Notes due 2016 and related Convertible Note Hedge and Warrants. |

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| - Definition
The entire disclosure for earnings per share.
+ References
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