Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Stock incentive plan and other information (Details)

v3.22.1
Stock-Based Compensation - Stock incentive plan and other information (Details) - USD ($)
3 Months Ended
Mar. 20, 2007
Mar. 31, 2022
Mar. 31, 2021
Dec. 31, 2021
Sep. 17, 2020
Sep. 05, 2019
Sep. 04, 2019
Sep. 24, 2018
Sep. 23, 2018
Sep. 07, 2017
Sep. 06, 2017
Aug. 25, 2016
Aug. 24, 2016
May 15, 2015
May 14, 2015
Oct. 22, 2013
Oct. 21, 2013
Nov. 02, 2010
Share-based Compensation Arrangement by Share-based Payment Award                                    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number       6,255,275                            
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross   0                                
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options   $ 624,000                                
General and Administrative Expense [Member] | Employees [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award                                    
Allocated Share-based Compensation Expense   59,000 $ 49,000                              
Consultant [Member] | General and Administrative Expenses and Research and Development Expense [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award                                    
Allocated Share-based Compensation Expense   $ 53,000 $ 52,000                              
2007 Stock Plan [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award                                    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number 71,429 5,145                                
2007 Stock Plan [Member] | Maximum                                    
Share-based Compensation Arrangement by Share-based Payment Award                                    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross 7,143                                  
Amended Stock Plan 2010                                    
Share-based Compensation Arrangement by Share-based Payment Award                                    
Common Stock, Capital Shares Reserved for Future Issuance           4,000,000 1,000,000 1,000,000 500,000 500,000 400,000 400,000 228,572 228,572 171,429 171,429 85,714  
2010 Stock Plan [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award                                    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number   3,668,333                               85,714
2010 Stock Plan [Member] | Board of Directors [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award                                    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number   2,434,237                                
2020 Stock Plan [Member]                                    
Share-based Compensation Arrangement by Share-based Payment Award                                    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number         4,000,000