Acquisitions, Goodwill and Intangible Assets (Details 3) $ in Thousands	3 Months Ended
Apr. 30, 2016 USD ($)
Finite-Lived Intangible Assets [Line Items]
Gross Fair Value	$ 62,360
Accumulated Amortization	(17,156)
Total	45,204
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross Fair Value	59,370
Accumulated Amortization	(14,873)
Total	$ 44,497
Weighted Average Remaining Useful Life	56 months
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Fair Value	$ 1,810
Accumulated Amortization	(1,439)
Total	$ 371
Weighted Average Remaining Useful Life	13 months
Other acquired intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Fair Value	$ 1,180
Accumulated Amortization	(844)
Total	$ 336
Weighted Average Remaining Useful Life	22 months

Weighted average amortization period of finite-lived intangible assets acquired either individually or as part of a group of assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16265-109275

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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