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Stock Purchase Warrants (Details) - $ / shares | 1 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Dec. 26, 2017 | Nov. 18, 2016 | Sep. 30, 2018 | Dec. 31, 2017
Closing Stock Price [Member] |  |  |  |
Closing stock price | $ 18.55 | $ 61.25 | $ 2.60 | $ 17.85
Expected Dividends [Member] |  |  |  |
Warrants, Measurement Input | 0.00% | 0.00% | 0.00% | 0.00%
Expected Volatility [Member] |  |  |  |
Warrants, Measurement Input | 85.00% | 95.00% | 90.00% | 80.00%
Risk Free Interest Rate [Member] |  |  |  |
Warrants, Measurement Input | 2.42% | 1.39% | 2.60% | 1.86%
Expected Life Of Warrant [Member] |  |  |  |
Expected life of warrant (years) | 4 years 11 months 1 day | 5 years | 1 year 14 days | 1 year 9 months 14 days
Series A Warrants [Member] | Closing Stock Price [Member] |  |  |  |
Closing stock price |  | $ 31.15 | $ 2.60 | $ 17.85
Series A Warrants [Member] | Expected Dividends [Member] |  |  |  |
Warrants, Measurement Input |  | 0.00% | 0.00% | 0.00%
Series A Warrants [Member] | Expected Volatility [Member] |  |  |  |
Warrants, Measurement Input |  | 85.00% | 80.00% | 80.00%
Series A Warrants [Member] | Risk Free Interest Rate [Member] |  |  |  |
Warrants, Measurement Input |  | 1.58% | 2.82% | 1.97%
Series A Warrants [Member] | Expected Life Of Warrant [Member] |  |  |  |
Expected life of warrant (years) |  | 4 years | 2 years 1 month 20 days | 2 years 10 months 24 days

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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 + Details
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