8. Stock-based Plans and Stock-based Compensation (Details) |
1 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended | ||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Nov. 06, 2018
shares
|
Feb. 07, 2018
USD ($)
$ / shares
shares
|
Aug. 14, 2017
USD ($)
employee
$ / shares
shares
|
May 15, 2017
USD ($)
employee
$ / shares
shares
|
Oct. 19, 2018
$ / shares
shares
|
Aug. 29, 2018
USD ($)
$ / shares
shares
|
Jun. 30, 2018
shares
|
Mar. 26, 2018
USD ($)
employee
$ / shares
shares
|
Feb. 23, 2018
shares
|
Dec. 21, 2017
USD ($)
$ / shares
shares
|
Nov. 30, 2017
USD ($)
employee
$ / shares
shares
|
Aug. 30, 2017
USD ($)
$ / shares
shares
|
Aug. 22, 2017
USD ($)
$ / shares
shares
|
Jul. 17, 2017
shares
|
Jun. 28, 2017
USD ($)
employee
$ / shares
shares
|
Jun. 27, 2017
USD ($)
$ / shares
shares
|
May 19, 2017
USD ($)
item
$ / shares
shares
|
Mar. 23, 2017
USD ($)
employee
item
$ / shares
shares
|
Dec. 31, 2018
USD ($)
employee
$ / shares
shares
|
Jun. 30, 2018
$ / shares
|
Mar. 31, 2018
shares
|
Jun. 30, 2018
USD ($)
employee
$ / shares
shares
|
Dec. 31, 2018
USD ($)
$ / shares
shares
|
Dec. 31, 2017
$ / shares
shares
|
Dec. 31, 2016
$ / shares
shares
|
Dec. 31, 2015
shares
|
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||||||||||||||||
| Shares authorized under stock plan | shares | 6,818,948 | 6,818,948 | ||||||||||||||||||||||||
| Shares available for future grants | shares | 733,933 | 733,933 | ||||||||||||||||||||||||
| Continuous service period | 4 years | |||||||||||||||||||||||||
| Options to purchase shares, in-the-money | shares | 3,079,500 | 3,079,500 | ||||||||||||||||||||||||
| Weighted average grant date fair value | $ / shares | $ 0.895 | $ 0.60 | $ 1.10 | $ 1.15 | $ 0.76 | |||||||||||||||||||||
| Number of employees, options granted | employee | 2 | 8 | 1 | 15 | 2 | 7 | 7 | 7 | ||||||||||||||||||
| Options granted | shares | 165,000 | 2,105,000 | 300,000 | 285,000 | 150,000 | 322,500 | 305,000 | 250,000 | ||||||||||||||||||
| Percent of shares vested on first anniversary of grant date | 25.00% | 25.00% | 25.00% | 25.00% | 25.00% | 25.00% | 25.00% | |||||||||||||||||||
| Monthly installments in which options vest, after initial vesting Anniversary | employee | 36 | 36 | 36 | 36 | 36 | 36 | 36 | |||||||||||||||||||
| Monthly installments in which options vest | employee | 48 | |||||||||||||||||||||||||
| Volatility rate | 86.00% | 85.00% | 102.00% | 84.00% | 86.00% | 86.00% | 84.00% | 84.00% | ||||||||||||||||||
| Call option value, price per share | $ / shares | $ 0.65 | $ 0.43 | $ .88 | $ 0.82 | $ 0.55 | $ 0.52 | $ 0.82 | $ .82 | ||||||||||||||||||
| Call option value | $ | $ 107,250 | $ 905,150 | $ 265,575 | $ 235,452 | $ 82,500 | $ 167,700 | $ 235,452 | $ 235,452 | ||||||||||||||||||
| Weighted average grant date fair value | $ / shares | $ 0.72 | $ 1.25 | $ 0.50 | |||||||||||||||||||||||
| Unearned stock based compensation expense | $ | $ 2,080,959 | $ 2,080,959 | ||||||||||||||||||||||||
| Shares issued | shares | 8,426 | 12,500 | 84,679 | 24,792 | 1,047,583 | 1,808 | 47,917 | 220,327 | 37,500 | 4,688 | 263,731 | 61,980 | 2,018,125 | |||||||||||||
| Shares Issued, Price Per Share | $ / shares | $ 0.78 | $ 1.20 | $ 0.48 | $ 0.48 | $ 0.75 | $ 0.41 | $ 0.48 | |||||||||||||||||||
| Proceeds from issuance of common stock, gross | $ | $ 9,595 | $ 11,875 | $ 23,000 | $ 28,125 | $ 1,922 | $ 29,750 | ||||||||||||||||||||
| Restricted stock units amortization | $ | 37,249 | |||||||||||||||||||||||||
| Board compensation | $ | $ 260,000 | |||||||||||||||||||||||||
| Minimum [Member] | ||||||||||||||||||||||||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||||||||||||||||
| Contractual terms (period) | 5 years | |||||||||||||||||||||||||
| Weighted average grant date fair value | $ / shares | $ 0.90 | $ 0.90 | ||||||||||||||||||||||||
| Volatility rate | 90.88% | 84.42% | ||||||||||||||||||||||||
| Maximum [Member] | ||||||||||||||||||||||||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||||||||||||||||
| Contractual terms (period) | 10 years | |||||||||||||||||||||||||
| Weighted average grant date fair value | $ / shares | $ 1.40 | $ 1.40 | ||||||||||||||||||||||||
| Volatility rate | 104.06% | 85.79% | ||||||||||||||||||||||||
| Employee Stock Option [Member] | ||||||||||||||||||||||||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||||||||||||||||
| Options granted | shares | 855,000 | 3,027,500 | ||||||||||||||||||||||||
| Options to purchase, expected to vest | shares | 3,001,272 | 3,001,272 | 6,818,948 | |||||||||||||||||||||||
| Weighted average exercise price | $ / shares | $ 1.15 | $ 1.15 | $ 1.06 | $ 1.37 | ||||||||||||||||||||||
| Restricted Stock Units R S U [Member] | ||||||||||||||||||||||||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||||||||||||||||
| Number of independent directors, restricted stock units granted | item | 4 | 5 | ||||||||||||||||||||||||
| Units issued | shares | 86,668 | 112,845 | 0 | 199,513 | 199,513 | |||||||||||||||||||||
| Value of units | $ | $ 65,001 | $ 81,248 | ||||||||||||||||||||||||
| Value of units, per share | $ / shares | $ 0.75 | $ 0.72 | $ 0.00 | $ 0.73 | $ 0.73 | |||||||||||||||||||||
| Number of monthly installments which units vest | item | 12 | 12 | ||||||||||||||||||||||||
| Performance Shares [Member] | ||||||||||||||||||||||||||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||||||||||||||||||||||||
| Units issued | shares | 1,000,000 | |||||||||||||||||||||||||
| Value of units | $ | $ 600,000 | |||||||||||||||||||||||||
| Value of units, per share | $ / shares | $ 0.60 | |||||||||||||||||||||||||