Segment And Geographic Information (Revenue By Geographic Area) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 17,770	$ 11,140
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	16,942	10,082
United Kingdom & Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 828	$ 1,058