Short-term Borrowings and Long-term Debt Schedule of Debt Maturities (Details) (USD $) In Millions, unless otherwise specified	Jan. 31, 2015	Jan. 31, 2014
Schedule of Short-Term Borrowings [Abstract]
2016	$ 4,810
2017	2,312
2018	1,523
2019	3,518
2020	514
Thereafter	33,219
Long-term Debt	$ 45,896us-gaap_LongTermDebt	$ 45,874us-gaap_LongTermDebt

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.

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

-Publisher SEC

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-Number 210

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Amount of long-term debt payable, sinking fund requirements, and other securities issued that are redeemable by holder at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

-Topic 235

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-Section S99

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-Subparagraph (SX 210.12-04.(a))

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