Stock-based Compensation - Stock-based Compensation Expense Recognized (Detail) - USD ($) |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2017 |
Sep. 30, 2016 |
Sep. 30, 2017 |
Sep. 30, 2016 |
|
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||||
| Total Stock based compensation | $ 127,440 | $ 225,427 | $ 422,206 | $ 468,992 |
| Discontinued Operations [Member] | ||||
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||||
| Total Stock based compensation | (21,585) | (21,318) | ||
| Research and Development [Member] | ||||
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||||
| Total Stock based compensation | (15,593) | 3,697 | (3,336) | (92,354) |
| General and Administrative [Member] | ||||
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||||
| Total Stock based compensation | $ 143,033 | $ 243,315 | $ 425,542 | $ 582,664 |