Segment Reporting - Deprecation and Amortization Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Depreciation	$ 3,532	$ 2,624	$ 9,939	$ 7,537
Amortization expense	277	251	833	740
Operating Segments | Mobile connectivity
Segment Reporting Information [Line Items]
Depreciation	2,963	2,160	8,263	6,159
Amortization expense	277	251	833	740
Operating Segments | Inertial navigation
Segment Reporting Information [Line Items]
Depreciation	397	318	1,165	934
Amortization expense	0	0	0	0
Unallocated
Segment Reporting Information [Line Items]
Depreciation	172	146	511	444
Amortization expense	$ 0	$ 0	$ 0	$ 0