Warrants - Summary of Assumptions Used to Estimate Fair Value of Warrants (Detail) - Common Stock Warrants [Member]	Jun. 30, 2019
Expected Volatility [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of warrants, measurement input	96.3
Expected Term (Years) [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of warrants, measurement input, expected term (years)	3 years 1 month 6 days
Risk-free Interest Rate [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of warrants, measurement input	1.7
Expected Dividend Yield [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value of warrants, measurement input	0.0

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.

No definition available.

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- Definition

Value of input used to measure outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

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- Definition

Period between issuance and expiration of outstanding warrant and right embodying unconditional obligation requiring redemption by transferring asset at specified or determinable date or upon event certain to occur, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

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