Segment Reporting - Deprecation and Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Depreciation	$ 2,402	$ 2,093
Amortization expense	248	248
Operating Segments | Mobile Connectivity
Segment Reporting Information [Line Items]
Depreciation	1,958	1,670
Amortization expense	248	248
Operating Segments | Intertial Navigation
Segment Reporting Information [Line Items]
Depreciation	293	286
Amortization expense	0	0
Segment Reconciling Items
Segment Reporting Information [Line Items]
Depreciation	151	137
Amortization expense	$ 0	$ 0