Allocation (Details Textual) - USD ($) $ in Millions  | 
1 Months Ended | 3 Months Ended | |
|---|---|---|---|
Jun. 30, 2017  | 
Mar. 31, 2018  | 
Mar. 31, 2017  | 
|
| Allocated Share-based Compensation Expense | $ 0.0 | $ 0.1 | |
| Share Based Compensation Allocation Percentage | 100.00% | ||
| Research and Development Expense [Member] | |||
| Share Based Compensation Allocation Percentage | 50.00% | ||
| General and Administrative Expense [Member] | |||
| Share Based Compensation Allocation Percentage | 50.00% | ||
| X | ||||||||||
- Definition The percentage of share based compensation expenses allocated to research and development and general and administrative expenses. No definition available. 
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| X | ||||||||||
- Definition Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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| X | ||||||||||
- Details 
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| X | ||||||||||
- Details 
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