Business and Summary of Significant Accounting Policies Geographical Concentration of Consolidated Cash, Cash Equivalents and Marketable Securities (Details)	12 Months Ended
Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2013 United States	Jan. 31, 2012 United States	Jan. 31, 2013 Other Americas	Jan. 31, 2012 Other Americas	Jan. 31, 2013 Europe, Middle East and Africa (EMEA)	Jan. 31, 2012 Europe, Middle East and Africa (EMEA)	Jan. 31, 2013 Asia Pacific (APAC)	Jan. 31, 2012 Asia Pacific (APAC)
Concentration Risk [Line Items]
Concentration Risk, Percentage	21.00%	22.00%	29.00%	11.00%	1.00%	1.00%	38.00%	51.00%	32.00%	37.00%

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 18

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

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=7491637&loc=d3e13537-108611

Reference 3: 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 4: 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=7491637&loc=d3e13531-108611

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