Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	12 Months Ended
Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2011
Statement of Other Comprehensive Income [Abstract]
Net income	$ 955	$ 951	$ 827
Other comprehensive (loss)/income
Foreign currency translation adjustments	(47)	(43)	58
Reclassification adjustments on derivatives, net of taxes of $2 for fiscal year 2011	0	0	3
Total other comprehensive (loss)/income	(47)	(43)	61
Comprehensive income	$ 908	$ 908	$ 888

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

+ References+ Details

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name Regulation S-X (SX)

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

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-Number 210

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

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-Glossary Net Income

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Reference 12: http://www.xbrl.org/2003/role/presentationRef

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Reference 14: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

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-Name Accounting Research Bulletin (ARB)

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Reference 16: http://www.xbrl.org/2003/role/presentationRef

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+ Details

- Definition

Amount after tax and reclassification adjustments, resulting from the process of expressing in the reporting currency of the reporting entity those amounts that are denominated or measured in a different currency, and from transactions whose terms are denominated in a currency other than the entity's functional currency, which is attributable to the parent entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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+ Details

- Definition

Net of tax amount of other comprehensive income (loss) attributable to the parent entity.

+ References

+ Details

- Definition

Net of tax amount of the income statement impact of the reclassification adjustment of accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges realized in net income. Also includes reclassification adjustments of an entity's share of an equity investee's deferred hedging gain (loss) realized in net income.

+ References

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

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-Glossary Reclassification Adjustments

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+ Details