Domestic and Foreign Revenues - Significant Foreign Revenues from Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Entity Wide Revenue Major Customer [Line Items]
Revenues from operations	$ 7,059	$ 7,838	$ 15,677	$ 14,470
Malaysia [Member]
Entity Wide Revenue Major Customer [Line Items]
Revenues from operations	563	854	1,581	1,679
Hong Kong [Member]
Entity Wide Revenue Major Customer [Line Items]
Revenues from operations	365	167	611	434
Australia [Member]
Entity Wide Revenue Major Customer [Line Items]
Revenues from operations	332	11	493	12
All other foreign countries [Member]
Entity Wide Revenue Major Customer [Line Items]
Revenues from operations	747	773	1,408	1,389
Foreign [Member]
Entity Wide Revenue Major Customer [Line Items]
Revenues from operations	2,007	1,805	4,093	3,514
Domestic [Member]
Entity Wide Revenue Major Customer [Line Items]
Revenues from operations	$ 5,052	$ 6,033	$ 11,584	$ 10,956