Fair Value Measurements and Concentrations of Credit Risk (Financial Assets Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	Jan. 28, 2012	Jan. 29, 2011
Marketable equity and debt securities	$ 81	$ 95
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Marketable equity and debt securities	0	41
Significant Observable Inputs (Level 2) [Member]
Marketable equity and debt securities	81	54
Significant Unobservable Inputs (Level 3) [Member]
Marketable equity and debt securities	$ 0	$ 0

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents investment securities as of the balance sheet date which may include marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References+ Details