Share-Based Compensation (Schedule Of Share-Based Compensation Expense Included In Statement Of Income) (Details) (USD $) In Thousands	3 Months Ended	6 Months Ended
Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2011	Jul. 31, 2010
Share-based compensation expense	$ 2,305	$ 2,327	$ 4,884	$ 4,527
Stock Options [Member]
Share-based compensation expense	502	1,010	1,321	2,006
Stock Appreciation Rights [Member]
Share-based compensation expense	256		513
Performance Share Units [Member]
Share-based compensation expense	1,544	1,317	3,044	2,521
Restricted Shares [Member]
Share-based compensation expense	$ 3		$ 6

The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 28
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

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Balance Type:	debit
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