Accrued Liabilities - Components of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Payables And Accruals [Abstract]
Accrued compensation and benefits	$ 9,049	$ 8,637
Accrued warranty	6,184	4,153
Acquired customer product commitments	546	858
Corporate income tax payable	3,186	1,415
Contingent earnout amount	874
VAT payable	1,789
Accrued satellite network and other equipment	245	595
Accrued inventory purchases	705	1,598
Accrued interest expense	10,000	4,944
Accrued professional fees	408	303
Accrued airtime charges	948	1,670
Other accrued expenses	8,038	8,843
Total accrued liabilities	$ 41,972	$ 33,016