Intangible Assets Amortization (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Apr. 30, 2020	Jan. 31, 2020
Finite-Lived Intangible Assets
Gross Fair Value	$ 341,610	$ 341,610
Accumulated Amortization	(117,926)	(103,195)
Total	223,684	238,415
Developed technology
Finite-Lived Intangible Assets
Gross Fair Value	252,530	252,530
Accumulated Amortization	(97,485)	(87,112)
Total	$ 155,045	$ 165,418
Weighted Average Remaining Useful Life	66 months	68 months
Customer relationships
Finite-Lived Intangible Assets
Gross Fair Value	$ 81,810	$ 81,810
Accumulated Amortization	(16,403)	(12,403)
Total	$ 65,407	$ 69,407
Weighted Average Remaining Useful Life	50 months	53 months
Other acquired intangible assets
Finite-Lived Intangible Assets
Gross Fair Value	$ 7,270	$ 7,270
Accumulated Amortization	(4,038)	(3,680)
Total	$ 3,232	$ 3,590
Weighted Average Remaining Useful Life	29 months	32 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.

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-Publisher FASB
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Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 928
-SubTopic 340
-Section 50
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