For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6404-108592

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 21

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13537-108611

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

-Section 50

-Paragraph 20

-URI http://asc.fasb.org/extlink&oid=6947722&loc=d3e13531-108611

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 275

-SubTopic 10

-Section 50

-Paragraph 18

-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6351-108592

Name:	us-gaap_ConcentrationRiskPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Business and Summary of Significant Accounting Policies Geographical Concentration of Consolidated Cash, Cash Equivalents and Marketable Securities (Details)	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2010
Concentration Risk [Line Items]
Concentration Risk, Percentage	21.00%	22.00%	21.00%
United States
Concentration Risk [Line Items]
Concentration Risk, Percentage	11.00%	14.00%
Other Americas
Concentration Risk [Line Items]
Concentration Risk, Percentage	1.00%	1.00%
Europe, Middle East and Africa (EMEA)
Concentration Risk [Line Items]
Concentration Risk, Percentage	51.00%	49.00%
Asia Pacific (APAC)
Concentration Risk [Line Items]
Concentration Risk, Percentage	37.00%	36.00%