Stock-based Compensation - Summary of Stock Option and Warrant Outstanding (Details) - $ / shares
|
9 Months Ended |
12 Months Ended |
|
Sep. 30, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
| Number outstanding |
433,535
|
706,262
|
111,129
|
| Weighted average remaining contractual life |
9 years 11 months 23 days
|
4 years 7 months 6 days
|
|
| Number exercisable |
|
|
|
| Weighted average exercise price exercisable |
|
|
|
| Exercise Price 0.11-0.55 [Member] |
|
|
|
| Exercise Prices |
$ 0.55
|
|
|
| Number outstanding |
261,372
|
|
|
| Weighted average remaining contractual life |
6 years 10 months 17 days
|
|
|
| Weighted average exercise price |
$ 0.55
|
|
|
| Number exercisable |
261,372
|
|
|
| Weighted average exercise price exercisable |
$ 0.55
|
|
|
| Exercise Price 2.00-3.85 [Member] |
|
|
|
| Number outstanding |
936,335
|
|
|
| Weighted average remaining contractual life |
9 years 5 months 1 day
|
|
|
| Weighted average exercise price |
$ 2.69
|
|
|
| Number exercisable |
369,668
|
|
|
| Weighted average exercise price exercisable |
$ 2.79
|
|
|
| Exercise Price 5.10-7.20 [Member] |
|
|
|
| Number outstanding |
408,535
|
|
|
| Weighted average remaining contractual life |
3 years 4 months 2 days
|
|
|
| Weighted average exercise price |
$ 5.46
|
|
|
| Number exercisable |
408,535
|
|
|
| Weighted average exercise price exercisable |
$ 5.46
|
|
|
| Exercise Price 0.11-7.20 [Member] |
|
|
|
| Number outstanding |
1,606,242
|
|
|
| Weighted average remaining contractual life |
7 years 5 months 16 days
|
|
|
| Weighted average exercise price |
$ 3.05
|
|
|
| Number exercisable |
1,039,575
|
|
|
| Weighted average exercise price exercisable |
$ 3.27
|
|
|
| Minimum [Member] | Exercise Price 2.00-3.85 [Member] |
|
|
|
| Exercise Prices |
2.00
|
|
|
| Minimum [Member] | Exercise Price 5.10-7.20 [Member] |
|
|
|
| Exercise Prices |
5.10
|
|
|
| Minimum [Member] | Exercise Price 0.11-7.20 [Member] |
|
|
|
| Exercise Prices |
0.11
|
|
|
| Maximum [Member] | Exercise Price 2.00-3.85 [Member] |
|
|
|
| Exercise Prices |
3.85
|
|
|
| Maximum [Member] | Exercise Price 5.10-7.20 [Member] |
|
|
|
| Exercise Prices |
7.20
|
|
|
| Maximum [Member] | Exercise Price 0.11-7.20 [Member] |
|
|
|
| Exercise Prices |
$ 7.20
|
|
|