Domestic and Foreign Revenues - Significant Foreign Revenues from Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Entity Wide Revenue Major Customer [Line Items]
Revenues from operations	$ 31,162	$ 31,897
Malaysia [Member]
Entity Wide Revenue Major Customer [Line Items]
Revenues from operations	2,842	4,329
Hong Kong [Member]
Entity Wide Revenue Major Customer [Line Items]
Revenues from operations	1,211	919
Australia [Member]
Entity Wide Revenue Major Customer [Line Items]
Revenues from operations	974	13
All other foreign countries [Member]
Entity Wide Revenue Major Customer [Line Items]
Revenues from operations	2,383	3,239
Foreign [Member]
Entity Wide Revenue Major Customer [Line Items]
Revenues from operations	7,410	8,500
Domestic [Member]
Entity Wide Revenue Major Customer [Line Items]
Revenues from operations	$ 23,752	$ 23,397