Balance Sheet Components - Intangible Assets, Net (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jul. 31, 2019	Jul. 31, 2019	Jan. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 75,225	$ 75,225	$ 27,825
Accumulated Amortization	(11,566)	(11,566)	(7,707)
Net Carrying Amount	63,659	63,659	20,118
Technology patents
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Asset, Residual Value	9,000	9,000
Gross Carrying Value	19,125	19,125	10,125
Accumulated Amortization	(7,538)	(7,538)	(6,572)
Net Carrying Amount	$ 11,587	$ 11,587	3,553
Weighted-average remaining useful life (in years)	7 years	4 years 2 months 12 days
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 56,100	$ 56,100	17,700
Accumulated Amortization	(4,028)	(4,028)	(1,135)
Net Carrying Amount	$ 52,072	$ 52,072	$ 16,565
Weighted-average remaining useful life (in years)		6 years 6 months

The aggregate expected value at the end of their useful life of a major finite-lived intangible asset class acquired during the period either individually or as part of a group of assets (in either an asset acquisition or business combination). A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16265-109275

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- Definition

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
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
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- Definition

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
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6473545&loc=d3e61844-108004

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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- Definition

Remaining amortization period of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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