Commitments And Contingencies (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	May 31, 2019 ft²	Jan. 31, 2017 ft²
Commitments and Contingencies [Line Items]
Rent expense, including common area maintenance charges | $	$ 0.2	$ 0.1
Hayward, CA [Member]
Commitments and Contingencies [Line Items]
Lease term	5 years
Area Of Lease				15,700
Lease Amendment [Member]
Commitments and Contingencies [Line Items]
Area Of Lease			34,600