Exercise price per share or per unit of warrants or rights outstanding.

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-Name Accounting Standards Codification
-Topic 235
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Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

+ References

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-Topic 235
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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
-SubTopic 10
-Section 50
-Paragraph 2
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- Definition

Fair value portion of warrants not settleable in cash classified as equity.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
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Stockholder's Equity - Warrants (Detail) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding (in shares)	5,496,971	4,406,004	2,712,954	3,468,991
Fair value of warrants		$ 6,000	$ 6,000
MidCap Financial Trust
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock (in shares)			84,986
Exercise price of warrants (in usd per share)			$ 3.53
Fair value of warrants			$ 50
CRG \| Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock (in shares)			1,701,582
Exercise price of warrants (in usd per share)			$ 2.38
Fair value of warrants			$ 4,500
CRG \| Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock (in shares)			349,451
Exercise price of warrants (in usd per share)			$ 3.42
Fair value of warrants			$ 1,500
Warrants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding (in shares)	84,986
Warrants \| CRG
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding (in shares)	2,051,034