Revenue Recognition - Revenues Generated Following Geographic Regions (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenue	$ 4,419	$ 3,518
Operating Segments
Disaggregation of Revenue [Line Items]
Total revenue	4,419	3,518
Operating Segments | United States
Disaggregation of Revenue [Line Items]
Total revenue	2,223	2,011
Operating Segments | United Kingdom
Disaggregation of Revenue [Line Items]
Total revenue	679	687
Operating Segments | Rest of World
Disaggregation of Revenue [Line Items]
Total revenue	$ 1,517	$ 820