Summary of Significant Accounting Policies - Additional Information (Detail)	1 Months Ended	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 05, 2013 USD ($)	Dec. 31, 2014 USD ($) Customer segment	Sep. 26, 2014 segment	Dec. 31, 2015 USD ($) Customer		Dec. 31, 2015 USD ($) Customer		Dec. 31, 2015 USD ($) Customer		Dec. 31, 2015 USD ($) Customer segment		Dec. 31, 2014 USD ($) Customer segment	Dec. 31, 2013 USD ($) Customer
Operating activities						$ (12,948,000)						$ (21,571,000)	$ (23,024,000)
Cash and cash equivalents maximum maturity				3 months								3 months	3 months
Revenue recognition period, associated with service and maintenance agreement				1 year
Percentage of revenue recognized upon completion contract method								100.00%
Number of reporting units								2		2		1	1
Goodwill, Impairment Loss						0						$ 0	$ 0
Capitalized Computer Software, Impairments												1,100,000
Foreign Currency Transaction Gain (Loss), before Tax						500,000						400,000	500,000
Advertising expense						$ 1,400,000						200,000	400,000
More Likely Than Not Threshold Recognition of Uncertain Tax Position				50.00%		50.00%		50.00%		50.00%
Number of reportable segments | segment		2	1							2
Reduction to Deferred Tax Assets, Unrecognized Tax Benefits, Tax Credit Carryforward from Prior Periods						$ 300,000						0	100,000
Service						100,151,000						90,371,000	$ 85,342,000
Restricted Cash and Investments, Current		$ 0		$ 1,093,000	[1]	1,093,000	[1]	$ 1,093,000	[1]	$ 1,093,000	[1]	$ 0
Unamortized Debt Issuance Expense				3,223,000		3,223,000		3,223,000		3,223,000
Deferred Tax Assets, Net of Valuation Allowance, Noncurrent				$ 15,900,000		$ 15,900,000		$ 15,900,000		$ 15,900,000
Furniture and fixtures [Member]
Property, plant and equipment estimated useful life				5 years
Internal Use Software [Member]
Property, plant and equipment estimated useful life				3 years
Machinery and equipment [Member]
Property, plant and equipment estimated useful life				4 years
Leasehold Improvements [Member]
Property, plant and equipment estimated useful life				10 years
Property, plant and equipment leasehold improvements useful lives				shorter of the remaining useful lives of the assets, up to ten years, or the lease term of the respective assets
Forward Contracts [Member]
Derivative, Term of Contract				12 months
Forward Contracts [Member] | Designated as Hedging Instrument [Member]
Derivative, Term of Contract				12 months
Software [Member]
Property, plant and equipment estimated useful life				3 years
Accounts Receivable [Member]
Number of significant customers for accounts receivable | Customer		0		0		0		0		0		0
Entity-wide revenue, major customer, revenue or accounts receivable percentage								10.00%				10.00%
Net Revenue [Member]
Entity-wide revenue, major customer, revenue or accounts receivable percentage								10.00%
Number Of Customers Accounting For More Than Ten Percent Of Revenue Other Than Comcast | Customer		0		0		0		0		0		0	0
Net Revenue [Member] | Comcast [Member]
Entity-wide revenue, major customer, revenue or accounts receivable percentage								12.00%				16.00%	12.00%
Customer Concentration Risk [Member] | Net Revenue [Member] | Comcast [Member]
Entity-wide revenue, major customer, revenue or accounts receivable percentage								12.00%				16.00%	12.00%
HFC business [Member]
Gross proceeds from sale of cable access HFC business	$ 46,000,000
HFC Restructuring [Member]
Operating activities						$ 0						$ 0

[1] (3) The restricted cash balances are held as cash collateral security for certain bank guarantees. These restricted funds are invested in bank deposits and cannot be withdrawn from the Company’s accounts without the prior written consent of the applicable secured party.