Stock-based Compensation - Additional Information (Detail) $ / shares in Units, $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($) $ / shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Closing stock price as reported on the Nasdaq \| $ / shares	$ 1.57
Weighted average fair value of options granted \| $ / shares	$ 0.99
Unrecognized compensation cost related to options granted after adjustment for estimated forfeitures \| $	$ 2.1
Expected weighted average remaining period to recognize total unrecognized compensation cost	2 years 4 months 24 days
RSU [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected weighted average remaining period to recognize total unrecognized compensation cost	2 years 10 months 17 days
Total unrecognized compensation cost, adjusted for estimated forfeitures, related to RSUs \| $	$ 0.6

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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 (i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

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- Definition

Unrecognized cost of unvested options awarded to employees as compensation.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ 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
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-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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- Definition

Price of a single share of a number of saleable stocks of a company.

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