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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6351-108592

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13531-108611

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118260190&loc=d3e13537-108611

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

Name:	us-gaap_ConcentrationRiskPercentage1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Summary of Significant Accounting Policies - Concentration of Credit Risk and Geographic Information (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 31, 2019 Distributor	Jul. 31, 2018 Distributor	Jul. 31, 2019 Distributor	Jul. 31, 2018 Distributor	Jan. 31, 2019 customer
Channel partners \| Revenue
Concentration Risk [Line Items]
Number of distributors \| Distributor	1	1	1	1
Concentration risk, percentage	11.00%	15.00%	11.00%	16.00%
Customers \| Accounts receivable
Concentration Risk [Line Items]
Number of customers \| customer					2
Customers \| Accounts receivable \| Customer 1
Concentration Risk [Line Items]
Concentration risk, percentage			10.00%
Customers \| Accounts receivable \| Customer 2
Concentration Risk [Line Items]
Concentration risk, percentage			19.00%