Stockholders' Equity (Narrative) (Details) | Jul. 02, 2019USD ($)$ / sharesshares | Jun. 28, 2019USD ($) | Jun. 21, 2018shares | Apr. 17, 2018USD ($) | Apr. 13, 2018agreement$ / sharesshares | Sep. 30, 2019$ / sharesshares | Sep. 30, 2019USD ($)$ / sharesshares | Jun. 26, 2019$ / sharesshares | Dec. 31, 2018$ / sharesshares |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Common stock, shares issued | | | | | | 97,238,427 | 97,238,427 | | 75,501,394 |
Proceeds from public offering | $ | $ 2,092,500 | $ 13,800,000 | | $ 13,500,000 | | | | | |
Preferred stock, shares issued | | | | | | 0 | 0 | | 0 |
Preferred stock, par value | $ / shares | | | | | | $ 0.001 | $ 0.001 | | $ 0.001 |
Shares converted | | | | | | | 50,000 | | |
2019 Stock Incentive Plan [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Share based compensation shares reserved for issuance | | | | | | 10,492,283 | 10,492,283 | | |
Share based compensation shares authorized for grants | | | | | | 10,492,283 | 10,492,283 | | |
2019 Stock Incentive Plan [Member] | Stock Option [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Granted | | | | | | | 195,000 | | |
2019 Stock Incentive Plan [Member] | Certain Officers And Employees [Member] | $0.52 [Member] | Stock Option [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Granted | | | | | | 95,000 | 95,000 | | |
Stock options granted, average exercise price | $ / shares | | | | | | $ 0.52 | $ 0.52 | | |
2019 Stock Incentive Plan [Member] | Certain Officers And Employees [Member] | $0.52 [Member] | Stock Option [Member] | Year Four Anniversary [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Vesting percentage | | | | | | 25.00% | | | |
2019 Stock Incentive Plan [Member] | Certain Officers And Employees [Member] | $1.01 [Member] | Stock Option [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Granted | | | | | | | 100,000 | | |
Stock options granted, average exercise price | $ / shares | | | | | | $ 1.01 | $ 1.01 | | |
2019 Stock Incentive Plan [Member] | Certain Officers And Employees [Member] | $1.01 [Member] | Stock Option [Member] | Year Four Anniversary [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Vesting percentage | | | | | | | 25.00% | | |
2010 Stock Incentive Plan [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Share based compensation shares reserved for issuance | | | | | | 6,985,007 | 6,985,007 | | |
2010 Stock Incentive Plan [Member] | Non-Employee Directors [Member] | Restricted Stock [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Restricted shares granted | | | | | | | 190,909 | | |
Fair value of restricted share units | $ | | | | | | | $ 252,000 | | |
2010 Stock Incentive Plan [Member] | Non-Employee Directors [Member] | Restricted Stock [Member] | April 1, 2019 [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Vesting percentage | | | | | | | 25.00% | | |
2010 Stock Incentive Plan [Member] | Non-Employee Directors [Member] | Restricted Stock [Member] | June 1, 2019 [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Vesting percentage | | | | | | | 25.00% | | |
2010 Stock Incentive Plan [Member] | Non-Employee Directors [Member] | Restricted Stock [Member] | September 1, 2019 [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Vesting percentage | | | | | | | 25.00% | | |
2010 Stock Incentive Plan [Member] | Non-Employee Directors [Member] | Restricted Stock [Member] | December 1, 2019 [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Vesting percentage | | | | | | | 25.00% | | |
2010 Stock Incentive Plan [Member] | Non-Employee Directors [Member] | $1.29 [Member] | Stock Option [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Granted | | | | | | | 402,584 | | |
Stock options granted, average exercise price | $ / shares | | | | | | $ 1.29 | $ 1.29 | | |
2010 Stock Incentive Plan [Member] | Certain Consultants [Member] | Restricted Stock [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Restricted shares granted | | | | | | | 11,667 | | |
Fair value of restricted share units | $ | | | | | | | $ 10,000 | | |
2010 Stock Incentive Plan [Member] | Certain Consultants [Member] | $0.47 [Member] | Stock Option [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Granted | | | | | | | 50,000 | | |
Stock options granted, average exercise price | $ / shares | | | | | | 0.47 | $ 0.47 | | |
2010 Stock Incentive Plan [Member] | Certain Consultants [Member] | $1.29 [Member] | Stock Option [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Granted | | | | | | | 100,000 | | |
Stock options granted, average exercise price | $ / shares | | | | | | 1.29 | $ 1.29 | | |
2010 Stock Incentive Plan [Member] | Certain Consultants [Member] | $1.28 [Member] | Stock Option [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Granted | | | | | | | 35,001 | | |
Stock options granted, average exercise price | $ / shares | | | | | | 1.28 | $ 1.28 | | |
2010 Stock Incentive Plan [Member] | Certain Officers And Employees [Member] | $0.47 [Member] | Stock Option [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Granted | | | | | | | 575,000 | | |
Stock options granted, average exercise price | $ / shares | | | | | | 0.47 | $ 0.47 | | |
2010 Stock Incentive Plan [Member] | Certain Officers And Employees [Member] | $0.71 [Member] | Stock Option [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Granted | | | | | | | 55,000 | | |
Stock options granted, average exercise price | $ / shares | | | | | | 0.71 | $ 0.71 | | |
2010 Stock Incentive Plan [Member] | Certain Officers And Employees [Member] | $0.77 [Member] | Stock Option [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Granted | | | | | | | 125,000 | | |
Stock options granted, average exercise price | $ / shares | | | | | | 0.77 | $ 0.77 | | |
2010 Stock Incentive Plan [Member] | Certain Officers And Employees [Member] | $1.29 [Member] | Stock Option [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Granted | | | | | | | 1,073,000 | | |
Stock options granted, average exercise price | $ / shares | | | | | | 1.29 | $ 1.29 | | |
2010 Stock Incentive Plan [Member] | Certain Officers And Employees [Member] | $1.29 [Member] | Stock Option [Member] | Year Four Anniversary [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Vesting percentage | | | | | | | 25.00% | | |
2010 Stock Incentive Plan [Member] | Certain Officers And Employees [Member] | $1.28 [Member] | Stock Option [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Granted | | | | | | | 14,000 | | |
Stock options granted, average exercise price | $ / shares | | | | | | 1.28 | $ 1.28 | | |
2010 Stock Incentive Plan [Member] | Certain Officers And Employees [Member] | $1.13 [Member] | Stock Option [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Granted | | | | | | | 20,000 | | |
Stock options granted, average exercise price | $ / shares | | | | | | $ 1.13 | $ 1.13 | | |
2019 Offerings [Member] | Common Stock [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Common stock, shares issued | 2,812,500 | | | | | | | 18,750,000 | |
Price per share | $ / shares | $ 0.80 | | | | | | | | |
Underwriting agreement, per share | $ / shares | | | | | | | | $ 0.80 | |
Underwriting agreement | | | | | | | | 2,812,500 | |
Proceeds from public offering | $ | $ 2,092,500 | $ 13,800,000 | | | | | | | |
2018 Offerings [Member] | Series B Convertible Preferred Stock [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Underwriting agreement, per share | $ / shares | | | | | $ 100 | | | | |
Proceeds from public offering | $ | | | | $ 4,496,000 | | | | | |
Preferred stock, shares issued | | | | | 50,000 | | | | |
Preferred stock, par value | $ / shares | | | | | $ 0.001 | | | | |
Percentage of underwriting costs and other offering costs | | | | 7.00% | | | | | |
Shares converted | | | 50,000 | | | | | | |
2018 Offerings [Member] | Common Stock [Member] | | | | | | | | | |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | | | | | | | | | |
Number of underwriting agreements | agreement | | | | | 2 | | | | |
Common stock, shares issued | | | | | 10,000,000 | | | | |
Underwriting agreement, per share | $ / shares | | | | | $ 1 | | | | |
Underwriting agreement | | | | | 1,500,000 | | | | |
Proceeds from public offering | $ | | | | $ 8,990,000 | | | | | |
Common stock issuable per preferred share | | | 100 | | | | | | |
Percentage of underwriting costs and other offering costs | | | | 7.00% | | | | | |