Stock-based Compensation - Stock-based Compensation Expense Recognized (Detail) - USD ($) |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2017 |
Jun. 30, 2016 |
Jun. 30, 2017 |
Jun. 30, 2016 |
|
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||||
| Total Stock based compensation | $ 122,748 | $ 37,804 | $ 294,766 | $ 243,565 |
| Discontinued Operations [Member] | ||||
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||||
| Total Stock based compensation | 39 | 267 | ||
| Research and Development [Member] | ||||
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||||
| Total Stock based compensation | 5,643 | (129,684) | 12,257 | (96,051) |
| General and Administrative [Member] | ||||
| Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] | ||||
| Total Stock based compensation | $ 117,105 | $ 167,449 | $ 282,509 | $ 339,349 |