Accrued Liabilities - Components of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Payables And Accruals [Abstract]
Accrued compensation and benefits	$ 6,515	$ 7,082
Warranty	1,995	2,321
Corporate income tax payable	243	204
Contingent consideration	1,322
Accrued satellite network and other equipment	748	1,642
Accrued inventory purchases	2,840	1,676
Milestone payable	5,070	3,185
Accrued interest expense	1,019	1,017
Accrued airtime charges	894	834
Other accrued expenses	6,753	6,225
Total accrued liabilities	$ 27,399	$ 24,186