Financial Instruments - Additional information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
Apr. 30, 2011	Apr. 28, 2012 Derivatives Designated as Hedging Instruments Foreign Exchange Forward	Apr. 28, 2012 Derivatives Designated as Non-Hedging Instruments Foreign Exchange Forward	Apr. 28, 2012 Derivatives Designated as Non-Hedging Instruments Diesel fuel forward and option contracts
Derivative [Line Items]
Net change in fair value of foreign exchange derivative financial instruments designated as cash flow hedges of the purchase of inventory	$ 3
Notional value of contracts outstanding		$ 51	$ 36	$ 5
Derivative contracts maturity date		2013-01	2012-07	2012-11

Aggregate notional amount of all derivatives. The notional amount relates to a number of currency units, shares, bushels, pounds, or other units specified in a derivative instrument.

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

-URI http://asc.fasb.org/extlink&oid=6519104

Name:	us-gaap_NotionalAmountOfDerivatives
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant