Balance Sheet Components (Schedule Of Accrued Expenses) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Balance Sheet Components [Abstract]
Compensation expense	$ 2,276	$ 1,699
Accrued clinical	268	262
Professional fees	8	51
Property and equipment	262	234
Director and officer liability insurance	938
Other	359	250
Accrued expenses	$ 4,111	$ 2,496