Income Taxes (Components Of Deferred Tax Balances) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income Tax Disclosure [Abstract]
Receivable allowances	$ 83	$ 94
Deferred revenue	72us-gaap_DeferredTaxAssetsDeferredIncome	136us-gaap_DeferredTaxAssetsDeferredIncome
Compensation and benefit related accruals	681	632
Net operating loss and credit carryforwards	316	337
Other	266us-gaap_DeferredTaxAssetsOther	287us-gaap_DeferredTaxAssetsOther
Subtotal	1,418us-gaap_DeferredTaxAssetsGross	1,486us-gaap_DeferredTaxAssetsGross
Less: valuation allowance	(229)	(200)
Total assets	1,189us-gaap_DeferredTaxAssetsNet	1,286us-gaap_DeferredTaxAssetsNet
Inventory valuation and other assets	(2,333)	(2,161)
Fixed assets and systems development costs	(324)	(320)
Intangibles	(1,073)	(1,477)
Other	(61)us-gaap_DeferredTaxLiabilitiesOther	(117)us-gaap_DeferredTaxLiabilitiesOther
Total liabilities	(3,791)us-gaap_DeferredIncomeTaxLiabilities	(4,075)us-gaap_DeferredIncomeTaxLiabilities
Net deferred tax liability	(2,602)us-gaap_DeferredTaxLiabilities	(2,789)us-gaap_DeferredTaxLiabilities
Current net deferred tax asset	26	42
Current net deferred tax liability	(1,819)	(1,588)
Long-term deferred tax asset	50	19
Long-term deferred tax liability	$ (859)	$ (1,262)

Deferred Tax Liabilities, Gross Net By Jurisdiction

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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards, net of deferred tax liability attributable to taxable temporary differences expected to be realized or consumed within one year or operating cycle, if longer.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from compensation and benefits costs.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from the allowance for doubtful accounts.

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Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Amount of deferred tax consequences attributable to taxable temporary differences derived from inventory.

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Amount of deferred tax liability attributable to taxable temporary differences from intangible assets other than goodwill.

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Amount of deferred tax liability attributable to taxable temporary differences, net of deferred tax asset attributable to deductible temporary differences and carryforwards net of valuation allowances expected to be realized or consumed after one year (or the normal operating cycle, if longer).

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Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment.

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