Summary of Significant Accounting Policies - Additional Information (Detail)		3 Months Ended		12 Months Ended
	Mar. 01, 2016 OG2Satellite	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Dec. 31, 2018 USD ($) Satellite Customer Segment	Dec. 31, 2017 USD ($) Customer	Dec. 31, 2016 USD ($) Customer
Summary Of Significant Accounting Policies [Line Items]
Equity method investments				$ 0	$ 0
Guarantee or other funding obligations under equity method investment				0	0	$ 0
Earnings or losses from equity method investment				0	0	0
Acquisition-related and integration costs				1,624,000	3,315,000	1,630,000
Revenue recognized from customer contracts				$ 5,236,000	6,114,000
Number of satellite networks buying network connectivity | Customer				2
Number of terrestrial network partners buying network connectivity | Customer				7
Foreign currency translation gain (loss)				$ (76,000)	(374,000)	$ (4,000)
Note payable - related party				1,298,000	1,366,000
Cash and cash equivalents				$ 53,766,000	$ 34,830,000
Number of customers with revenues greater than 10% | Customer				0		0
Number of customers with accounts receivable greater than 10% | Customer				0	0
Inventories finished goods and purchased parts				$ 27,701,000	$ 34,465,000
Inventories raw materials				$ 6,599,000	7,972,000
Interest capitalized						$ 744,000
Impairment loss – satellite network					31,224,000	10,680,000
Number of reporting segments | Segment				1
Goodwill impairment charges				$ 0	$ 0	0
Maximum percentage of benefit realized upon ultimate settlement				50.00%
Revenues [Member] | Customer Concentration Risk [Member] | JB Hunt Transport Services, Inc. [Member]
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage					10.80%
Gateway Earth Stations [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of assets operated communications and broadcasting equipment | Satellite				15
AIS Data Reception Earth Stations [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of assets operated communications and broadcasting equipment | Satellite				3
Regional Gateway Control Centers [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of assets operated communications and broadcasting equipment | Satellite				3
OG2 Satellite [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of satellites placed in service | OG2Satellite	11
Impairment loss – satellite network		$ 31,224,000	$ 10,680,000	$ 0	$ 31,224,000	10,680,000
Satellite Network [Member]
Summary Of Significant Accounting Policies [Line Items]
Impairment loss on asset						$ 466,000
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization of internal use software costs, useful life				3 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Amortization of internal use software costs, useful life				7 years
ASU 2014-09 [Member]
Summary Of Significant Accounting Policies [Line Items]
Warranty period				1 year
Estimated life of communicator				3 years
ASU 2014-09 [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Additional term of the agreement				2 years
ASU 2014-09 [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Additional term of the agreement				5 years
ASU 2016-02 [Member] | Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated operating lease right-of-use asset and liability				$ 10,000,000
ASU 2016-02 [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated operating lease right-of-use asset and liability				$ 15,000,000