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Warrants - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			6 Months Ended
	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018	Apr. 30, 2012
Debt Disclosure [Abstract]
Warrants issued (in shares)							992,000
Right to purchase, number of shares per warrant (in shares)							1
Exercise price of warrants (in dollars per warrant)							$ 10.00
Warrant liability, at fair value				$ 9,679		$ 7,296	$ 5,100
Warrants exercised (in shares)				260,000	63,000
Stock issued upon exercise of warrants (in shares)	39,195	3,751	25,686	168,000	29,000
Fair value of warrant liability reclassified to additional paid in capital upon exercise				$ 4,800	$ 600
Change in fair value of warrant liability in current period				$ 2,300	$ 42

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- Definition

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- Definition

Class Of Warrant Or Right, Fair Value Of Warrant Liability Reclassified To Additional Paid In Capital Upon Exercise

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- Definition

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
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- Definition

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.

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Number of shares issued during the period as a result of the conversion of convertible securities.

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Value of outstanding derivative securities that permit the holder the right to purchase securities (usually equity) from the issuer at a specified price.

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