Stockholders' Equity - Stock-based Compensation Expense (Details) - USD ($) |
3 Months Ended | |
---|---|---|
Mar. 31, 2019 |
Mar. 31, 2018 |
|
Stock-based compensation expense | ||
Total stock based compensation expense | $ 200,067 | $ 1,406,131 |
Options vested, fair value | 188,984 | 971,488 |
Research and Development Expense | ||
Stock-based compensation expense | ||
Total stock based compensation expense | 110,081 | 395,709 |
Cost of Revenue | ||
Stock-based compensation expense | ||
Total stock based compensation expense | 0 | 39,631 |
Selling, general and administrative expense | ||
Stock-based compensation expense | ||
Total stock based compensation expense | 89,986 | 970,791 |
Stock Option | ||
Stock-based compensation expense | ||
Unrecognized compensation cost | $ 165,954 | $ 2,662,066 |
Weighted-average remaining vesting period for recognition | 9 months 29 days | 1 year 9 months 15 days |
Options outstanding, weighted average contractual life | 7 years 2 months 9 days |