Balance Sheet Components (Schedule Of Accrued Expenses) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Balance Sheet Components [Abstract]
Compensation expense	$ 1,917	$ 1,699
Accrued clinical	282	262
Professional fees	62	51
Property and equipment	234	234
Other	628	250
Accrued expenses	$ 3,123	$ 2,496