Segment Reporting (Details Textual)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Mobile Connectivity | Mobile Comm Product Sales
Segment Reporting Information [Line Items]
Percent of Consolidated Net Sales	18.00%	20.00%
Mobile Connectivity | VSAT Airtime Service Sales
Segment Reporting Information [Line Items]
Percent of Consolidated Net Sales	46.00%	41.00%
Mobile Connectivity | Training and Content Sales
Segment Reporting Information [Line Items]
Percent of Consolidated Net Sales	16.00%	19.00%
Intertial Navigation | FOG System Sales
Segment Reporting Information [Line Items]
Percent of Consolidated Net Sales	13.00%
Non-US
Segment Reporting Information [Line Items]
Percent of Consolidated Net Sales	62.00%	58.00%
Percent of consolidated long-lived tangible assets (less than)	10.00%		10.00%