Commitments And Contingencies (Expense Associated with Operating Leases) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Cost Of Revenue [Member]
Operating rent expense	$ 19	$ 9	$ 52	$ 27
Variable rent expense	2	13	6	37
Research And Development [Member]
Operating rent expense	13	2	37	9
Variable rent expense		3	1	9
Sales And Marketing [Member]
Operating rent expense	8	9	18	26
Variable rent expense	12	12	34	32
General And Administrative [Member]
Operating rent expense	18	11	45	33
Variable rent expense	$ 14	$ 16	$ 41	$ 44