Summary of Significant Accounting Policies - Additional Information (Detail)		3 Months Ended				12 Months Ended
	Mar. 01, 2016 USD ($) Satellite	Sep. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2016 USD ($) Satellite Customer Segment	Dec. 31, 2015 USD ($) Customer	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Equity method investments				$ 0		$ 0	$ 0
Guarantee or other funding obligations under equity method investment				0		0	0	$ 0
Losses from equity method investment						0	0	0
Acquisition-related and integration costs						$ 1,630,000	4,803,000	3,819,000
Warranty period						1 year
Number of satellite networks buying network connectivity | Customer						2
Number of terrestrial network partners buying network connectivity | Customer						7
Foreign currency translation gain (loss)						$ (4,000)	413,000	207,000
Cash and cash equivalents				27,077,000		$ 25,023,000	$ 27,077,000	91,565,000	$ 68,354,000
Number of customers with revenues greater than 10% | Customer						0	0
Inventories finished goods and purchased parts				16,912,000		$ 14,531,000	$ 16,912,000
Inventories raw materials				3,800,000		8,686,000	3,800,000
Interest capitalized						744,000	4,688,000	4,713,000
Impairment charges - satellite network						$ 10,680,000	12,748,000	605,000
Number of reporting segments | Segment						1
Goodwill impairment charges						$ 0	$ 0	$ 0
Impairment charge of intangible assets				$ 564,000
Maximum percentage of benefit realized upon ultimate settlement						50.00%
Caterpillar Inc. [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of customers with accounts receivable greater than 10% | Customer						1	1
Sales [Member] | Customer Concentration Risk [Member] | Caterpillar Inc. [Member]
Summary Of Significant Accounting Policies [Line Items]
Customers with revenues greater than 10%								12.40%
Sales [Member] | Customer Concentration Risk [Member] | Komatsu Ltd. [Member]
Summary Of Significant Accounting Policies [Line Items]
Customers with revenues greater than 10%								10.60%
Accounts Receivable | Customer Concentration Risk [Member] | Caterpillar Inc. [Member]
Summary Of Significant Accounting Policies [Line Items]
Customers with revenues greater than 10%						10.50%	11.60%
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 Satellites [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of satellites placed in service | Satellite	11
Reclassification of costs out of assets under construction into satellite network	$ 137,772,000
Satellites, life in years	10 years
Impairment loss on asset		$ 10,680,000			$ 12,748,000
Satellite Network [Member]
Summary Of Significant Accounting Policies [Line Items]
Satellites, life in years						10 years
Impairment loss on asset			$ 466,000					$ 605,000
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated life of communicator						4 years
Additional term of the agreement						2 years
Amortization of internal use software costs, useful life						3 years
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Estimated life of communicator						5 years
Additional term of the agreement						5 years
Amortization of internal use software costs, useful life						7 years