Revenue Recognition - Summary Disaggregation of Revenue by Region (Details) - USD ($) $ in Thousands	3 Months Ended
Apr. 30, 2019	Apr. 30, 2018
Disaggregation Of Revenue [Line Items]
Revenue	$ 121,988	$ 60,070
Percentage of revenue	100.00%	100.00%
Americas [Member]
Disaggregation Of Revenue [Line Items]
Revenue	$ 98,160	$ 49,559
Percentage of revenue	80.00%	82.00%
Asia Pacific [Member]
Disaggregation Of Revenue [Line Items]
Revenue	$ 10,441	$ 4,742
Percentage of revenue	9.00%	8.00%
EMEA [Member]
Disaggregation Of Revenue [Line Items]
Revenue	$ 13,387	$ 5,769
Percentage of revenue	11.00%	10.00%

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045

Name:	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration