| Nature of Operations and Summary of Significant Accounting Policies (Tables)
 | 12 Months Ended | 
| Dec. 31, 2019 | 
|---|
| Schedule of Statement of Operations | The table below presents the impact
of the adoption of ASC 606 on our statement of operations for the year ended December 31, 2018.   
    |  |  | For the year ended December 31, 2018 |  |  
    |  |  | Under |  |  | Effect of |  |  | As Reported |  |  
    |  |  | ASC 605 |  |  | ASC 606 |  |  | Under ASC 606 |  |  
    | Revenues |  |  |  |  |  |  |  |  |  |  
    | Foundation revenues |  | $ | - |  |  | $ | 2,796,000 |  |  | $ | 2,796,000 |  |  
    | License revenues |  |  | 602,000 |  |  |  | (602,000 | ) |  |  | - |  |  
    | Total revenues |  |  | 804,000 |  |  |  | 2,194,000 |  |  |  | 2,998,000 |  |  
    | Loss from operations |  |  | (60,360,000 | ) |  |  | 2,194,000 |  |  |  | (58,166,000 | ) |  
    | Net loss |  |  | (58,865,000 | ) |  |  | 2,194,000 |  |  |  | (56,671,000 | ) |  
    | Basic and diluted loss per common share |  |  | (1.24 | ) |  |  | 0.05 |  |  |  | (1.19 | ) |  | 
| Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share | We did not include the following
potentially dilutive securities in the computation of diluted net loss per common share during the periods presented:   
    |  |  | For the years ended December 31, |  |  
    |  |  | 2019 |  |  | 2018 |  |  | 2017 |  |  
    | Warrants |  |  | 70,000 |  |  |  | 1,820,686 |  |  |  | 2,934,685 |  |  
    | Stock options |  |  | 6,055,395 |  |  |  | 5,841,805 |  |  |  | 5,429,727 |  |  
    | Total |  |  | 6,125,395 |  |  |  | 7,662,491 |  |  |  | 8,364,412 |  |  | 
| Schedule of Stock Based Compensation | The following table summarizes stock
option-based option compensation for 2019, 2018 and 2017, which was allocated as follows:   
    |  |  | For the years ended December 31, |  |  
    |  |  | 2019 |  |  | 2018 |  |  | 2017 |  |  
    | Research and development |  | $ | 3,932,000 |  |  | $ | 3,913,000 |  |  | $ | 1,668,000 |  |  
    | General and administrative |  |  | 3,406,000 |  |  |  | 4,265,000 |  |  |  | 2,976,000 |  |  
    | Stock option-based compensation expense included in operating expense |  |  | 7,338,000 |  |  |  | 8,178,000 |  |  |  | 4,644,000 |  |  
    |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Total stock option-based compensation expense |  |  | 7,338,000 |  |  |  | 8,178,000 |  |  |  | 4,644,000 |  |  
    | Tax benefit |  |  | - |  |  |  | - |  |  |  | - |  |  
    | Stock option-based compensation expense, net of tax |  | $ | 7,338,000 |  |  | $ | 8,178,000 |  |  | $ | 4,644,000 |  |  | 
| Restricted Stock [Member] |  | 
| Schedule of Stock Based Compensation | The following table summarizes restricted
stock-based compensation for 2019, 2018 and 2017, which was allocated as follows:   
    |  |  | For the years ended December 31, |  |  
    |  |  | 2019 |  |  | 2018 |  |  | 2017 |  |  
    | Research and development |  | $ | 454,000 |  |  | $ | - |  |  | $ | - |  |  
    | General and administrative |  |  | 445,000 |  |  |  | 688,000 |  |  |  | 1,272,000 |  |  
    | Restricted stock-based compensation expense included in operating expense |  |  | 899,000 |  |  |  | 688,000 |  |  |  | 1,272,000 |  |  
    |  |  |  |  |  |  |  |  |  |  |  |  |  |  
    | Total restricted stock-based compensation expense |  |  | 899,000 |  |  |  | 688,000 |  |  |  | 1,272,000 |  |  
    | Tax benefit |  |  | - |  |  |  | - |  |  |  | - |  |  
    | Restricted stock-based compensation expense, net of tax |  | $ | 899,000 |  |  | $ | 688,000 |  |  | $ | 1,272,000 |  |  |