Summary of Business and Significant Accounting Policies (Fair Value of Outstanding Derivative Instruments) (Details) (Foreign Currency Derivative Contracts [Member], USD $) In Thousands	Apr. 30, 2011	Jan. 31, 2011
Prepaid Expenses and Other Current Assets [Member]
Derivative assets	$ 407	$ 1,539
Accrued Expenses and Other Current Liabilities [Member]
Derivative liabilities	$ 4,673	$ 2,863

Fair value of a derivative liability that is not designated or qualifying as a hedging instrument, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 133
-Paragraph 205G

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 133
-Paragraph 44C
-Subparagraph a
-Clause 1

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant