Summary of Significant Accounting Policies (Details Textual) $ / shares in Units, $ in Thousands		3 Months Ended		12 Months Ended
	Feb. 28, 2018 USD ($) $ / shares shares	Mar. 31, 2018 hub	Dec. 31, 2016 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jan. 01, 2019 USD ($)
Accounting Policies [Line Items]
Gain on settlement of royalty payments			$ 855
Sale of treasury stock (in shares) | shares	377,000
Purchase price (in USD per share) | $ / shares	$ 11.95
Sale of treasury stock	$ 4,500			$ 4,500	$ 0	$ 0
Capital lease term		5 years
Satellite hubs leased | hub		3
Concentration of Credit Risk and Single Source Suppliers
Marketable securities				25	8,319
Advertising Costs
Advertising expense				1,954	2,739	2,761
Foreign Currency Translation
Foreign currency transaction gain, before tax				$ 497	$ 554	$ (53)
Minimum
Accounting Policies [Line Items]
Sales-type lease period				3 years
Sales-type lease interest rate				5.00%
Maximum
Accounting Policies [Line Items]
Sales-type lease period				5 years
Sales-type lease interest rate				8.50%
Revenue-generating assets
Accounting Policies [Line Items]
Property, plant and equipment, useful lives				P5Y
Accounting Standards Update 2016-02 | Minimum
Foreign Currency Translation
Right-to-use assets							$ 12,000
Lease liabilities							12,000
Accounting Standards Update 2016-02 | Maximum
Foreign Currency Translation
Right-to-use assets							15,000
Lease liabilities							$ 15,000