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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 |

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