Segment Reporting (Details Textual) - Sales	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Product Sales Concentration Risk | Mobile Connectivity
Segment Reporting Information [Line Items]
Concentration Risk, Percentage	18.00%	20.00%	23.00%
Geographic Concentration Risk | Non-US
Segment Reporting Information [Line Items]
Concentration Risk, Percentage	61.00%	62.00%	63.00%
Geographic Concentration Risk | Canada
Segment Reporting Information [Line Items]
Concentration Risk, Percentage			11.00%
Mini-VSAT Broadband Airtime Service | Service Sales Concentration Risk | Mobile Connectivity
Segment Reporting Information [Line Items]
Concentration Risk, Percentage	41.00%	41.00%	37.00%
Content and Training Services | Service Sales Concentration Risk | Mobile Connectivity
Segment Reporting Information [Line Items]
Concentration Risk, Percentage	17.00%	20.00%	20.00%
FOG-based Guidance and Navigation Systems | Product Sales Concentration Risk | Intertial Navigation
Segment Reporting Information [Line Items]
Concentration Risk, Percentage	16.00%	13.00%	10.00%