CONSOLIDATED STATEMENTS OF CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2018
CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY
Issuance costs	$ 200	$ 400	$ 1,907

The cash outflow for cost incurred directly with the issuance of an equity security.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585

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