Stock-Based Compensation - Stock incentive plan and other information (Details) - USD ($)	3 Months Ended			6 Months Ended			12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2021	Dec. 31, 2020	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	Mar. 20, 2007
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number							625,527
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross				3,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options	$ 516,000			$ 516,000
Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	607,334			607,334				399,742
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross		0			0		226,000
General and Administrative Expense [Member] | Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Allocated Share-based Compensation Expense	$ 39,000	$ 34,000		$ 78,000	$ 67,000
Research and Development Expenses | Employees [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Allocated Share-based Compensation Expense	21,000	16,000		41,000	31,000
Consultant [Member] | General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Allocated Share-based Compensation Expense	46,000	$ 49,000		93,000	$ 98,000
Consultant [Member] | Research and Development Expenses
Share-based Compensation Arrangement by Share-based Payment Award
Allocated Share-based Compensation Expense	$ 7,000		$ 3,000	$ 14,000		$ 7,000
Employees
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross	3,000			3,000
Employees | General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Allocated Share-based Compensation Expense	$ 5,000,000			$ 5,000,000
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	515			515																			7,143
Amended Stock Plan 2010
Share-based Compensation Arrangement by Share-based Payment Award
Common Stock, Capital Shares Reserved for Future Issuance										400,000	100,000	100,000	50,000	50,000	40,000	40,000	22,858	22,858	17,143	17,143	8,572
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	368,000			368,000																		8,572
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	238,820			238,820
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									400,000