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Common Stock and Warrants - Warrants Outstanding and Exercisable (Details)	12 Months Ended
	Dec. 31, 2018 $ / shares shares	Dec. 31, 2018 $ / shares shares
Class Of Warrant Or Right [Line Items]
Number of Warrants Outstanding	4,004,304	4,004,304
Warrants Expiration Date, June 26, 2020
Class Of Warrant Or Right [Line Items]
Number of Warrants Outstanding	3,795	3,795
Exercise price | $ / shares	$ 10.75
Expiration Date	Jun. 26, 2020
Warrants Expiration Date, July 17, 2020
Class Of Warrant Or Right [Line Items]
Number of Warrants Outstanding	1,509	1,509
Exercise price | $ / shares	$ 10.75
Expiration Date	Jul. 17, 2020
Warrants Expiration Date, April 18, 2019
Class Of Warrant Or Right [Line Items]
Number of Warrants Outstanding	960,699	960,699
Exercise price | $ / shares		$ 7.50
Expiration Date	Apr. 18, 2019
Warrants Expiration Date, December 22, 2020
Class Of Warrant Or Right [Line Items]
Number of Warrants Outstanding	270,915	270,915
Exercise price | $ / shares	$ 12.25
Expiration Date	Dec. 22, 2020
Warrants Expiration Date, December 28, 2020
Class Of Warrant Or Right [Line Items]
Number of Warrants Outstanding	171,020	171,020
Exercise price | $ / shares	$ 12.25
Expiration Date	Dec. 28, 2020
Warrants Expiration Date, December 29, 2020
Class Of Warrant Or Right [Line Items]
Number of Warrants Outstanding	204,081	204,081
Exercise price | $ / shares	$ 12.25
Expiration Date	Dec. 29, 2020
Warrants Expiration Date, April 21, 2021
Class Of Warrant Or Right [Line Items]
Number of Warrants Outstanding	2,392,285	2,392,285
Exercise price | $ / shares		$ 12.25
Expiration Date	Apr. 21, 2021

X

- Definition

Expiration date of warrants held.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column A

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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Number of warrants or rights outstanding.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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