Discontinued Operations - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2015	Dec. 31, 2015 segment	Dec. 31, 2014 USD ($) segment	Dec. 31, 2013 USD ($)	Mar. 29, 2013 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Operating Income (Loss)	$ (12,948,000)			$ (21,571,000)	$ (23,024,000)
Net gain from sale of HFC business	0			$ 0	$ 14,663,000
Number of reporting units		2	2	1	1
HFC business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net gain from sale of HFC business					$ 14,663,000
Carrying value of goodwill based on the fair value					14,547,000	$ 14,500,000
HFC Restructuring [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Operating Income (Loss)	$ 0			$ 0
Aurora [Member] | HFC business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gross proceeds from sale of cable access HFC business					46,000,000
Net gain from sale of HFC business					$ 14,663,000