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Common Stock Reserved for Future Issuance (Details) - shares	Mar. 31, 2018	Mar. 31, 2017
Stockholders' equity
Shares reserved for future issuance (in shares)	5,400,278	4,229,689
Common stock warrants
Stockholders' equity
Shares reserved for future issuance (in shares)	24,566	24,566
Stock options
Stockholders' equity
Shares reserved for future issuance (in shares)	4,615,601	3,681,464
Employee Stock Purchase Plan
Stockholders' equity
Shares reserved for future issuance (in shares)	760,111	523,659

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- Definition

Aggregate number of common shares reserved for future issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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