Shareholders' Equity - Summary of Shares of Common Stock Reserved for Future Issuance under Plans (Detail) - shares	Jun. 30, 2019	Dec. 31, 2018
Common Stock Number Of Shares Par Value And Other Disclosures [Abstract]
Stock options outstanding	1,739,084	1,390,012
Restricted stock units outstanding	278,699
Stock options and restricted stock units available for future grant	1,532,966
Common stock reserved for future issuance	3,550,749

Share based compensation arrangement by share based payment award stock options and restricted stock units available for future grant.

No definition available.

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- Definition

Aggregate number of common shares reserved for future issuance.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)-(ii)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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- Definition

Number of options outstanding, including both vested and non-vested options.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-SubTopic 10
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-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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