Commitments And Contingencies (Narrative) (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	May 31, 2019 ft²	Jan. 31, 2017 ft²
Commitments and Contingencies [Line Items]
Rent expense, including common area maintenance charges | $	$ 0.5	$ 0.1	$ 1.2	$ 0.2
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