Short-term Borrowings and Long-term Debt (Long Term Debt Schedule of Maturities) (Details) (USD $) In Millions, unless otherwise specified	Jan. 31, 2014	Jan. 31, 2013
Debt Instrument [Line Items]
Long-term Debt Maturities - Fiscal Year 2015	$ 4,103
Long-term Debt Maturities - Fiscal Year 2016	4,480
Long-term Debt Maturities - Fiscal Year 2017	2,396
Long-term Debt Maturities - 2018	1,107
Long-term Debt Maturities - 2019	3,531
Long-term Debt Maturities - Thereafter	30,257
Long-term Debt	$ 45,874	$ 43,981

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Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year.

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the next fiscal year following the latest fiscal year.

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the fifth fiscal year following the latest fiscal year.

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the fourth fiscal year following the latest fiscal year.

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the third fiscal year following the latest fiscal year.

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Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the second fiscal year following the latest fiscal year.

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