Selected Statements of Operations Data (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Research and Development Assets Acquired Other than Through Business Combination [Line Items]
General and administrative expenses	$ 2,678	$ 2,936
Overseas Travel [Member]
Research and Development Assets Acquired Other than Through Business Combination [Line Items]
General and administrative expenses	103	118
Share Based Payment [Member]
Research and Development Assets Acquired Other than Through Business Combination [Line Items]
General and administrative expenses	688	783
Rent And Office Maintenance [Member]
Research and Development Assets Acquired Other than Through Business Combination [Line Items]
General and administrative expenses	49	46
Payroll And Benefits [Member]
Research and Development Assets Acquired Other than Through Business Combination [Line Items]
General and administrative expenses	470	518
Professional Services And Consultation [Member]
Research and Development Assets Acquired Other than Through Business Combination [Line Items]
General and administrative expenses	953	1,187
Taxes And Tolls [Member]
Research and Development Assets Acquired Other than Through Business Combination [Line Items]
General and administrative expenses	24	16
Director Salary And Insurance [Member]
Research and Development Assets Acquired Other than Through Business Combination [Line Items]
General and administrative expenses	183	191
Other Expenses [Member]
Research and Development Assets Acquired Other than Through Business Combination [Line Items]
General and administrative expenses	$ 208	$ 77