Geographic Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Geographic Information
Property and equipment, net	$ 3,479	$ 4,286
Revenue	37,503	49,417
Hong Kong
Geographic Information
Revenue	10,144	2,453
Germany
Geographic Information
Revenue	6,423	6,724
Japan
Geographic Information
Revenue	5,660	10,254
United States
Geographic Information
Property and equipment, net	2,235	2,714
Revenue	4,915	6,746
China
Geographic Information
Revenue	1,361	5,083
All other
Geographic Information
Property and equipment, net	455	660
Revenue	9,000	18,157
Singapore
Geographic Information
Property and equipment, net	$ 789	$ 912